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  • Javascript: adding methods using prototype descriptor

    - by LDK
    Sorter.prototype.init_bubblesort = function(){ console.log(this.rect_array); this.end = this.rect_array.length; this.bubblesort(); } Sorter.prototype.init = function(array,sort_type){ this.rect_array = array; this.init_bubblesort(); } The code above works as expected, but when I change the init function to: Sorter.prototype.init = function(array,sort_type){ var sort_types = {'bubblesort':this.init_bubblesort, 'quicksort':this.init_quicksort, 'liamsort':this.init_liamsort}; this.rect_array = array; sort_types[sort_type](); } the init_bubblesort function results in an error saying this.rect_array is undefined. I'm trying to wrap my head around why init_bubblesort no longer as access to it's instance's variables.

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  • JQuery code problem?

    - by SLAPme
    New to JQuery, I added the following JQuery code below and moved it around in my code and now it won't work I forgot what I did, can someone fix my code by placing the below code in its correct place thanks. $('a').click(function () { $('#changes-saved').remove(); }); return false; // prevent normal submit }); JQuery code. $(function() { $('#changes-saved').hide(); $('.save-button').click(function() { $.post($('#contact-form').attr('action'), $('#contact-form').serialize(), function(html) { $('div.contact-info-form').html(html); $('#changes-saved').append('Changes saved!').show().pause(1000).hide(); }); return false; // prevent normal submit }); $('a').click(function () { $('#changes-saved').remove(); }); return false; // prevent normal submit }); });

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  • How to strip debug code during compile time in C++?

    - by juvenis
    Say I have a C++ function debugPrint(int foo). How can I most conveniently strip that from release builds? I do not want to surround every call to debugPrint with #ifdefs as it would be really time consuming. On the other hand, I want to be 100% sure that the compiler strips all the calls to that function, and the function itself from release builds. The stripping should happen also, if it's called with a parameter that results from a function call. E.g., debugPrint(getFoo());. In that case I want also the getFoo() call to be stripped. I understand that function inlining could be an option, but inlining is not guaranteed to be supported.

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  • jQuery link nudge and color transform

    - by DaveKingsnorth
    Hey everyone, I have achieved the effect described in the title using the following code: $(document).ready(function(){ $('.button').mousedown(function() { $(this).animate({ 'top': '3px' }, 70); }); $('.button').mouseup(function() { $(this).animate({ 'top': '0px' }, 70); }); $('.button').hover(function() { $(this).stop().animate({ color: '#fff', backgroundColor: '#000' }, 250); }); $('.button').mouseout(function() { $(this).stop().animate({ color: '#000', backgroundColor: '#fff' }, 250); }); }); I am pretty sure that that this code can be reduced significantly, can anyone help me out? Please note that I want the button to animate when the mouse is clicked and not return to it's original position until the mouse is released. Cheers

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  • jquery animate() problem

    - by meo
    $('#somediv').stop(false, true).animate({marginLeft: '-=' + e.width() + 'px'}, options.speed, function(){ options.onNewSlide() }) e.with() returns 640 opctions.speed contains 800 options.onNewSlide() contains a a custom callback function It works fine in firefox. But i debugged it with jquery.lint because it was throwing some random error in IE. lint tells me: When I called animate(...) with your args, an error was thrown! TypeError: c.speed is not a function { message="c.speed is not a function", more...} You passed: [Object { marginLeft="-=640px"}, 800, function()] and it indicates me the line i have posted. I have checked the jquery doc, but my syntax seams ok. Do you know what i am doing wrong?

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  • jQuery does not execute on dynamically loaded content,, even on a click events.

    - by sxv
    I have two document.ready functions. The first loads content into div#header. The second one performs a hide function and then a toggle function on the newly loaded content. I am not sure if this is a queueing issue or something, but not even the alert() below is executed when I click the loaded content. Thanks. <script type="text/javascript"> $(document).ready(function() { $("#header").load("/documents/collegeradioheader.txt"); }); </script> <script type="text/javascript"> $(document).ready(function() { $(".hideme").hide(); $(".slick-toggle").click(function() { alert('hi'); $(this).parent().next('div').slideToggle('fast'); .siblings('div:visible').slideUp('fast'); }); }); </script>

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  • website inserting pics

    - by onfire4JesusCollins
    Hello i am getting this error message : Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.NullReferenceException: Object reference not set to an instance of an object. Source Error: Line 7: Line 8: Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load Line 9: UserIdValue.Text = Membership.GetUser().ProviderUserKey.ToString() Line 10: cannotUploadImageMessage.Visible = False Line 11: End Sub can someone help me with this?

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  • how to do collision detection for hollow(?) movieclips in flash AS3?

    - by Pieter888
    Hey everyone, I'm making small interactive games in flash to learn AS3, now I ran into a problem that I need some help with. I need to check the collision between the player and the wall which is normally simple using the hitTestObject function. But now I made a wall object totally surrounding the player with corridors and turn, a collision playground so to speak. Now when I use the hitTestObject function to check whether the player is in collision with the wall it tells me it always collides supposedly because the player object is within the bounds of the wall object. So assuming that I'm correct about the error: How can I prevent getting a collision when I'm inside the bounds of the wall object but not touching the actual walls in that object?

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  • How to reference filtered ng-repeat items from a controller in AngularJS

    - by ParkerDigital
    I have some JSON data that is rendered out via the ng-repeat directive, and the results are then filtered via some checkboxes/drop-downs, and some custom filter functions in my controller. I now want to add a function to my controller that is triggered by an 'ng-change' on some of the checkboxes, that can reference the current list of items in my 'ng-repeat'. I realise I can reference these values from a custom filter, for example $scope.filterProvider = function(item), but this function is then called for each and every item in the ng-repeat, which isn't what I want - I want the function to just be called each time a checkbox is checked/unchecked, and I need that function to be able to reference the items in my ng-repeat...does that make sense to anyone?! And if so, does anyone know how I can do that? Thanks :-)

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  • jquery autocomplete get selected item text

    - by rlee923
    I am wondering how to grab the selected item's text value on jquery autocomplete. I have initialised jquery as following : $(document).ready(function (){ $("input#autocomplete").autocomplete({ source: postcodelist, select: function (event, ui) { AutoCompleteSelectHandler(event, ui) } }); }); And I have created a function function AutoCompleteSelectHandler(event, ui) { }. Inside this function I want to some extra handling to feed data into correct textboxes but I can't figure out how to grab the text value of the selected item. I did google a bit and tried examples but I can't seem to get it working. Any help will be much appreciated. Thanks a lot advance.

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  • Can't get jQuery ajax work

    - by yozloy
    I'm new to jQuery, and it really cool, but I can't get the basic ajax work, there's no error in the console ,so I don't know where goes wrong: getJSON function version: $(document).ready(function(){ $.getJSON('http://pollview:8888/js/example.json', function(data){ for(var element in data){ console.log(data[element]); } }); }); then the basic ajax version: $(document).ready(function(){ $.ajax({ url: 'http://pollview:8888/js/example.json' }).done(function(data){ alert('successful'); }); }); I get me stuck, any idea?

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  • Rotate on hover using Jquery

    - by Ian34
    I can't figure out how to set up a jquery rotate function that would only rotate on hover. Here is the code that I am using: $('div.settingsButton').hover(function() { var angle = 0; setInterval(function() { angle += 4; $(this).rotate(angle); }, 50); }, function() { var angle = 0; setInterval(function() { angle = 0; $(this).rotate(angle); }, 50); }); The rotate is a plugin found here: http://code.google.com/p/jqueryrotate/

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  • Why isn't this working - using :not() with an event handler

    - by james emanon
    I seem to have another issue that I am not conquering. Real simple premise. I have a mousedown event, and basically IF one particular element on the page is clicked, I want nothing to happen, else I want hide() some div. $(function(){ $("document :not(#_ignorelement)").mousedown(function(event){ if($('#_hidethiselement').length){ $('#_hidethiselement').hide(); } }) }) That is not working at all. I also tried the following: $(document).not($("#_ignorelement")).mousedown(function(event){ $(document).not("_ignorelement").mousedown(function(event){ IF I can solve that, curious how I would actually have ":not" encompass the parent div, like so: $().not("_ignoreelement").parent().closest('div').mousedown(function Because the element "_ignorelement" is an anchor tag that is in a div. Wonder how I can use the parent div perhaps, instead of the anchor tag. Anyways, any help would be appreciated.

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  • Use of .apply() with 'new' operator. Is this possible?

    - by Premasagar
    In JavaScript, I want to create an object instance (via the new operator), but pass an arbitrary number of arguments to the constructor. Is this possible? What I want to do is something like this (but the code below does not work): function Something(){ // init stuff } function createSomething(){ return new Something.apply(null, arguments); } var s = createSomething(a,b,c); // 's' is an instance of Something The Answer From the responses here, it became clear that there's no in-built way to call .apply() with the new operator. However, people suggested a number of really interesting solutions to the problem. My preferred solution was this one from Matthew Crumley (I've modified it to pass the arguments property): var createSomething = (function() { function F(args) { return Something.apply(this, args); } F.prototype = Something.prototype; return function() { return new F(arguments); } })();

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  • Delphi 2009 - Strip non alpha numeric from string

    - by Brad
    I've got the following code, and need to strip all non alpha numeric characters. It's not working in delphi 2009 ` unit Unit2; //Used information from // http://stackoverflow.com/questions/574603/what-is-the-fastest-way-of-stripping-non-alphanumeric-characters-from-a-string-in interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; Type TExplodeArray = Array Of String; TForm2 = class(TForm) Memo1: TMemo; ListBox1: TListBox; Button1: TButton; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } Function Explode ( Const cSeparator, vString : String ) : TExplodeArray; Function Implode ( Const cSeparator : String; Const cArray : TExplodeArray ) : String; Function StripHTML ( S : String ) : String; function allwords(data:string):integer; end; var Form2: TForm2; allword, allphrase: TExplodeArray; implementation {$R *.dfm} Function TForm2.StripHTML ( S : String ) : String; Var TagBegin, TagEnd, TagLength : Integer; Begin TagBegin := Pos ( '<', S ); // search position of first < While ( TagBegin > 0 ) Do Begin // while there is a < in S TagEnd := Pos ( '>', S ); // find the matching > TagLength := TagEnd - TagBegin + 1; Delete ( S, TagBegin, TagLength ); // delete the tag TagBegin := Pos ( '<', S ); // search for next < End; Result := S; // give the result End; Function TForm2.Implode ( Const cSeparator : String; Const cArray : TExplodeArray ) : String; Var i : Integer; Begin Result := ''; For i := 0 To Length ( cArray ) - 1 Do Begin Result := Result + cSeparator + cArray [i]; End; System.Delete ( Result, 1, Length ( cSeparator ) ); End; Function TForm2.Explode ( Const cSeparator, vString : String ) : TExplodeArray; Var i : Integer; S : String; Begin S := vString; SetLength ( Result, 0 ); i := 0; While Pos ( cSeparator, S ) 0 Do Begin SetLength ( Result, Length ( Result ) + 1 ); Result[i] := Copy ( S, 1, Pos ( cSeparator, S ) - 1 ); Inc ( i ); S := Copy ( S, Pos ( cSeparator, S ) + Length ( cSeparator ), Length ( S ) ); End; SetLength ( Result, Length ( Result ) + 1 ); Result[i] := Copy ( S, 1, Length ( S ) ); End; //Copied from JclStrings function StrKeepChars(const S: AnsiString; const Chars: TSysCharSet): AnsiString; var Source, Dest: PChar; begin SetLength(Result, Length(S)); UniqueString(Result); Source := PChar(S); Dest := PChar(Result); while (Source < nil) and (Source^ < #0) do begin if Source^ in Chars then begin Dest^ := Source^; Inc(Dest); end; Inc(Source); end; SetLength(Result, (Longint(Dest) - Longint(PChar(Result))) div SizeOf(AnsiChar)); end; function ReplaceNewlines(const AValue: string): string; var SrcPtr, DestPtr: PChar; begin SrcPtr := PChar(AValue); SetLength(Result, Length(AValue)); DestPtr := PChar(Result); while SrcPtr < {greater than less than} #0 do begin if (SrcPtr[0] = #13) and (SrcPtr[1] = #10) then begin DestPtr[0] := '\'; DestPtr[1] := 't'; Inc(SrcPtr); Inc(DestPtr); end else DestPtr[0] := SrcPtr[0]; Inc(SrcPtr); Inc(DestPtr); end; SetLength(Result, DestPtr - PChar(Result)); end; function StripNonAlphaNumeric(const AValue: string): string; var SrcPtr, DestPtr: PChar; begin SrcPtr := PChar(AValue); SetLength(Result, Length(AValue)); DestPtr := PChar(Result); while SrcPtr < #0 do begin if SrcPtr[0] in ['a'..'z', 'A'..'Z', '0'..'9'] then begin DestPtr[0] := SrcPtr[0]; Inc(DestPtr); end; Inc(SrcPtr); end; SetLength(Result, DestPtr - PChar(Result)); end; function TForm2.allwords(data:string):integer; var i:integer; begin listbox1.Items.add(data); data:= StripHTML ( data ); listbox1.Items.add(data); ////////////////////////////////////////////////////////////// data := StrKeepChars(data, ['A'..'Z', 'a'..'z', '0'..'9']); // Strips out everything data comes back blank in Delphi 2009 ////////////////////////////////////////////////////////////// listbox1.Items.add(data); data := stringreplace(data,' ',' ', [rfReplaceAll, rfIgnoreCase] ); //Replace two spaces with one. listbox1.Items.add(data); allword:= explode(' ',data); { // Converting the following PHP code to Delphi $text = ereg_replace("[^[:alnum:]]", " ", $text); while(strpos($text,' ')!==false) $text = ereg_replace(" ", " ", $text); $text=$string=strtolower($text); $text=explode(" ",$text); return count($text); } for I := 0 to Length(allword) - 1 do listbox1.Items.Add(allword[i]); end; procedure TForm2.Button1Click(Sender: TObject); begin //[^[:alnum:]] allwords(memo1.Text); end; end. ` How else would I go about doing this? Thanks

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  • Jquery append input for 2 different input-sections

    - by Email
    Hi i use the following simple jquery script to append input. Source http://muiomuio.com/web-design/add-remove-items-with-jquery <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> <title>Add and Remove - jQuery tutorial</title> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" type="text/javascript"></script> <script type="text/javascript"> $(function() { var i = $('input').size() + 1; $('a.add').click(function() { $('<p><input type="text" value="input ' + i + '" name="input_field'+ i +'" /></p>').animate({ opacity: "show" }, "slow").appendTo('#inputs'); i++; }); $('a.remove').click(function() { if(i > 2) { $('input:last').animate({opacity:"hide"}, "slow").remove(); i--; } }); $('a.reset').click(function() { while(i > 2) { $('input:last').remove(); i--; } }); }); </script> </head> <body> <h1>Add / remove text fields from webform</h1> <a href="#" class="add"><img src="add.png" width="24" height="24" alt="add" title="add input" /></a> <a href="#" class="remove"><img src="remove.png" width="24" height="24" alt="remove input" /></a> <a href="#" class="reset"><img src="reset.png" width="24" height="24" alt="reset" /></a> <div id="inputs"> <p> <input type="text" value="input 1" name="input_field1"> </p> </div> </div> </body> </html> I know want to add more input fields so i add this html <div id="outputs"> <p> <input type="text" value="output 1" name="output_field1"> </p> how can i achieve that the var i = $('input').size() + 1; will be individually for every input section? EDITED: the full script is the following. copy and paste will get you a full clone of mine. Problem still exists <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> <title>Add and Remove - jQuery tutorial</title> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" type="text/javascript"></script> <script type="text/javascript"> $(function() { var i = $('input').size() + 1; $('a.add').click(function() { $('<p><input type="text" value="input ' + i + '" name="input_field'+ i +'" /></p>').animate({ opacity: "show" }, "slow").appendTo('#inputs'); i++; }); $('a.remove').click(function() { if(i > 2) { $('input:last').animate({opacity:"hide"}, "slow").remove(); i--; } }); $('a.reset').click(function() { while(i > 2) { $('input:last').remove(); i--; } }); $('a.add_o').click(function() { $('<p><input type="text" value="output ' + i + '" name="input_field'+ i +'" /></p>').animate({ opacity: "show" }, "slow").appendTo('#outputs'); i++; }); $('a.remove_o').click(function() { if(i > 2) { $('input:last').animate({opacity:"hide"}, "slow").remove(); i--; } }); $('a.reset_o').click(function() { while(i > 2) { $('input:last').remove(); i--; } }); }); </script> <style rel="stylesheet" type="text/css"> h1 { font-family:"Trebuchet MS", Arial, Helvetica, sans-serif;} .hide {visibility:hidden;} img {border:none;} input { width:500px; height:20px; padding:10px; background:#f7f7f7; border:1px solid #f0f0f0; color:#333; font-size:20px; text-align:center; line-height:120px; margin:0; -moz-border-radius:5px; -webkit-border-radius:5px; } #inputs { width:520px; padding:0px 20px; border:1px solid #f0f0f0; -moz-border-radius:20px; -webkit-border-radius:20px; } </style> </head> <body> <h1>Add / remove text fields from webform</h1> <a href="#" class="add"><img src="http://muiomuio.com/tutorials/jquery/add-remove/add.png" width="24" height="24" alt="add" title="add input" /></a> <a href="#" class="remove"><img src="http://muiomuio.com/tutorials/jquery/add-remove/remove.png" width="24" height="24" alt="remove input" /></a> <a href="#" class="reset"><img src="http://muiomuio.com/tutorials/jquery/add-remove/reset.png" width="24" height="24" alt="reset" /></a> <div id="inputs"> <p> <input type="text" value="input 1" name="input_field1"> </p> </div> <a href="#" class="add_o"><img src="http://muiomuio.com/tutorials/jquery/add-remove/add.png" width="24" height="24" alt="add" title="add input" /></a> <a href="#" class="remove_o"><img src="http://muiomuio.com/tutorials/jquery/add-remove/remove.png" width="24" height="24" alt="remove input" /></a> <a href="#" class="reset_o"><img src="http://muiomuio.com/tutorials/jquery/add-remove/reset.png" width="24" height="24" alt="reset" /></a> <div id="outputs"> <p> <input type="text" value="output 1" name="output_field1"> </p> </div> </body> </html>

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  • YUI Uploader hangs after choosing file

    - by stephenbayer
    Below is my entire code from a User control that contains the YUI Uploader. Is there something I'm missing. Right now, when I step through the javascript code in Firebug, it hangs on the first line of the upload() function. I have a breakpoint on the first line of the ashx that handles the file, but it is never called. So, it doesn't get that far. I figure I'm just missing something stupid. I've used this control many times before with no issues. I'm using all the css files and graphics provided by the samples folder in the YUI download. If I'm not missing anything, is there a more comprehensive way of debuging this issue then through stepping through the javascript with FireBug. I've tried turning the logging for YUI on and off, and never get any logs anywhere. I'm not sure where to go now. <style type="text/css"> #divFile { background-color:White; border:2px inset Ivory; height:21px; margin-left:-2px; margin-right:9px; width:125px; } </style> <ajaxToolkit:RoundedCornersExtender runat="server" Corners="All" Radius="6" ID="rceContainer" TargetControlID="pnlMMAdmin" /> <asp:Panel ID="pnlMMAdmin" runat="server" Width="100%" BackColor="Silver" ForeColor="#ffffff" Font-Bold="true" Font-Size="16px"> <div style="padding: 5px; text-align:center; width: 100%;"> <table style="width: 100% ; border: none; text-align: left;"> <tr> <td style="width: 460px; vertical-align: top;"> <!-- information panel --> <ajaxToolkit:RoundedCornersExtender runat="server" Corners="All" Radius="6" ID="RoundedCornersExtender1" TargetControlID="pnlInfo" /> <asp:Panel ID="pnlInfo" runat="server" Width="100%" BackColor="Silver" ForeColor="#ffffff" Font-Bold="true" Font-Size="16px"> <div id="infoPanel" style="padding: 5px; text-align:left; width: 100%;"> <table> <tr><td>Chart</td><td> <table><tr><td><div id="divFile" ></div></td><td><div id="uploaderContainer" style="width:60px; height:25px"></div></td></tr> <tr><td colspan="2"><div id="progressBar"></div></td></tr></table> </td></tr> </table> </div></asp:Panel> <script type="text/javascript" language="javascript"> WYSIWYG.attach('<%= txtComment.ClientID %>', full); var uploader = new YAHOO.widget.Uploader("uploaderContainer", "assets/buttonSkin.jpg"); uploader.addListener('contentReady', handleContentReady); uploader.addListener('fileSelect', onFileSelect) uploader.addListener('uploadStart', onUploadStart); uploader.addListener('uploadProgress', onUploadProgress); uploader.addListener('uploadCancel', onUploadCancel); uploader.addListener('uploadComplete', onUploadComplete); uploader.addListener('uploadCompleteData', onUploadResponse); uploader.addListener('uploadError', onUploadError); function handleContentReady() { // Allows the uploader to send log messages to trace, as well as to YAHOO.log uploader.setAllowLogging(false); // Restrict selection to a single file (that's what it is by default, // just demonstrating how). uploader.setAllowMultipleFiles(false); // New set of file filters. var ff = new Array({ description: "Images", extensions: "*.jpg;*.png;*.gif" }); // Apply new set of file filters to the uploader. uploader.setFileFilters(ff); } var fileID; function onFileSelect(event) { for (var item in event.fileList) { if (YAHOO.lang.hasOwnProperty(event.fileList, item)) { YAHOO.log(event.fileList[item].id); fileID = event.fileList[item].id; } } uploader.disable(); var filename = document.getElementById("divFile"); filename.innerHTML = event.fileList[fileID].name; var progressbar = document.getElementById("progressBar"); progressbar.innerHTML = "Please wait... Starting upload.... "; upload(fileID); } function upload(idFile) { // file hangs right here. ************************** progressBar.innerHTML = "Upload starting... "; if (idFile != null) { uploader.upload(idFile, "AdminFileUploader.ashx", "POST"); fileID = null; } } function handleClearFiles() { uploader.clearFileList(); uploader.enable(); fileID = null; var filename = document.getElementById("divFile"); filename.innerHTML = ""; var progressbar = document.getElementById("progressBar"); progressbar.innerHTML = ""; } function onUploadProgress(event) { prog = Math.round(300 * (event["bytesLoaded"] / event["bytesTotal"])); progbar = "<div style=\"background-color: #f00; height: 5px; width: " + prog + "px\"/>"; var progressbar = document.getElementById("progressBar"); progressbar.innerHTML = progbar; } function onUploadComplete(event) { uploader.clearFileList(); uploader.enable(); progbar = "<div style=\"background-color: #f00; height: 5px; width: 300px\"/>"; var progressbar = document.getElementById("progressBar"); progressbar.innerHTML = progbar; alert('File Uploaded'); } function onUploadStart(event) { alert('upload start'); } function onUploadError(event) { alert('upload error'); } function onUploadCancel(event) { alert('upload cancel'); } function onUploadResponse(event) { alert('upload response'); } </script>

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  • vertical accordion from horizontal

    - by Sify Juhy
    //# jQuery - Horizontal Accordion //# Version 2.00.00 Alpha 1 //# //# portalZINE(R) - New Media Network //# http://www.portalzine.de //# //# Alexander Graef //# [email protected] //# //# Copyright 2007-2009 (function($) { $.hrzAccordion = { setOnEvent: function(i, container, finalWidth, settings){ $("#"+container+"Handle"+i).bind(settings.eventTrigger,function() { var status = $('[rel='+container+'ContainerSelected]').data('status'); if(status ==1 && settings.eventWaitForAnim === true){ return false; } if( $("#"+container+"Handle"+i).attr("rel") != container+"HandleSelected"){ settings.eventAction; $('[id*='+container+'Handle]').attr("rel",""); $('[id*='+container+'Handle]').attr("class",settings.handleClass); $("#"+container+"Handle"+i).addClass(settings.handleClassSelected); $("."+settings.contentWrapper).css({width: finalWidth+"px" }); switch(settings.closeOpenAnimation) { case 1: if($('[rel='+container+'ContainerSelected]').get(0) ){ $('[rel='+container+'ContainerSelected]').data('status',1); //current_width = $('[rel='+container+'ContainerSelected]').width(); $('[rel='+container+'ContainerSelected]').animate({width: "0px",opacity:"0"}, { queue:true, duration:settings.closeSpeed ,easing:settings.closeEaseAction,complete: function(){ $('[rel='+container+'ContainerSelected]').data('status',0); } ,step: function(now){ width = $(this).width(); //new_width = finalWidth- (finalWidth * (width/current_width)); new_width = finalWidth - width; $('#'+container+'Content'+i).width(Math.ceil(new_width)).css("opacity","1"); }}); }else{ $('[rel='+container+'ContainerSelected]').data('status',1); $('#'+container+'Content'+i).animate({width: finalWidth,opacity:"1"}, { queue:false, duration:settings.closeSpeed ,easing:settings.closeEaseAction,complete: function(){ $('[rel='+container+'ContainerSelected]').data('status',0); }}); } break; case 2: $('[id*='+container+'Content]').css({width: "0px"}); $('#'+container+'Content'+i).animate({width: finalWidth+"px",opacity:"1"}, { queue:false, duration:settings.openSpeed ,easing:settings.openEaseAction, complete: settings.completeAction }); break; } $('[id*='+container+'Content]').attr("rel",""); $("#"+container+"Handle"+i).attr("rel",container+"HandleSelected"); $("#"+container+"Content"+i).attr("rel",container+"ContainerSelected"); } }); } }; $.fn.extend({ hrzAccordionLoop: function(options) { return this.each(function(a){ var container = $(this).attr("id") || $(this).attr("class"); var elementCount = $('#'+container+' > li, .'+container+' > li').size(); var settings = $(this).data('settings'); variable_holder="interval"+container ; var i =0; var loopStatus = "start"; variable_holder = window.setInterval(function(){ $("#"+container+"Handle"+i).trigger(settings.eventTrigger); if(loopStatus =="start"){ i = i + 1; }else{ i = i-1; } if(i==elementCount && loopStatus == "start"){ loopStatus = "end"; i=elementCount-1; } if(i==0 && loopStatus == "end"){ loopStatus = "start"; i=0; } },settings.cycleInterval); }); }, hrzAccordion: function(options) { this.settings = { eventTrigger : "click", containerClass : "container", listItemClass : "listItem", contentContainerClass : "contentContainer", contentWrapper : "contentWrapper", contentInnerWrapper : "contentInnerWrapper", handleClass : "handle", handleClassOver : "handleOver", handleClassSelected : "handleSelected", handlePosition : "right", handlePositionArray : "", // left,left,right,right,right closeEaseAction : "swing", closeSpeed : 500, openEaseAction : "swing", openSpeed : 500, openOnLoad : 2, hashPrefix : "tab", eventAction : function(){ //add your own extra clickAction function here }, completeAction : function(){ //add your own onComplete function here }, closeOpenAnimation : 1,// 1 - open and close at the same time / 2- close all and than open next cycle : false, // not integrated yet, will allow to cycle through tabs by interval cycleInterval : 10000, fixedWidth : "", eventWaitForAnim : true }; if(options){ $.extend(this.settings, options); } var settings = this.settings; return this.each(function(a){ var container = $(this).attr("id") || $(this).attr("class"); $(this).data('settings', settings); $(this).wrap("<div class='"+settings.containerClass+"'></div>"); var elementCount = $('#'+container+' > li, .'+container+' > li').size(); var containerWidth = $("."+settings.containerClass).width(); var handleWidth = $("."+settings.handleClass).css("width"); handleWidth = handleWidth.replace(/px/,""); var finalWidth; var handle; if(settings.fixedWidth){ finalWidth = settings.fixedWidth; }else{ finalWidth = containerWidth-(elementCount*handleWidth)-handleWidth; } $('#'+container+' > li, .'+container+' > li').each(function(i) { $(this).attr('id', container+"ListItem"+i); $(this).attr('class',settings.listItemClass); $(this).html("<div class='"+settings.contentContainerClass+"' id='"+container+"Content"+i+"'>" +"<div class=\""+settings.contentWrapper+"\">" +"<div class=\""+settings.contentInnerWrapper+"\">" +$(this).html() +"</div></div></div>"); if($("div",this).hasClass(settings.handleClass)){ var html = $("div."+settings.handleClass,this).attr("id",""+container+"Handle"+i+"").html(); $("div."+settings.handleClass,this).remove(); handle = "<div class=\""+settings.handleClass+"\" id='"+container+"Handle"+i+"'>"+html+"</div>"; }else{ handle = "<div class=\""+settings.handleClass+"\" id='"+container+"Handle"+i+"'></div>"; } if(settings.handlePositionArray){ splitthis = settings.handlePositionArray.split(","); settings.handlePosition = splitthis[i]; } switch(settings.handlePosition ){ case "left": $(this).prepend( handle ); break; case "right": $(this).append( handle ); break; case "top": $("."+container+"Top").append( handle ); break; case "bottom": $("."+container+"Bottom").append( handle ); break; } $("#"+container+"Handle"+i).bind("mouseover", function(){ $("#"+container+"Handle"+i).addClass(settings.handleClassOver); }); $("#"+container+"Handle"+i).bind("mouseout", function(){ if( $("#"+container+"Handle"+i).attr("rel") != "selected"){ $("#"+container+"Handle"+i).removeClass(settings.handleClassOver); } }); $.hrzAccordion.setOnEvent(i, container, finalWidth, settings); if(i == elementCount-1){ $('#'+container+",."+container).show(); } if(settings.openOnLoad !== false && i == elementCount-1){ var location_hash = location.hash; location_hash = location_hash.replace("#", ""); if(location_hash.search(settings.hashPrefix) != '-1' ){ var tab = 1; location_hash = location_hash.replace(settings.hashPrefix, ""); } if(location_hash && tab ==1){ $("#"+container+"Handle"+(location_hash)).attr("rel",container+"HandleSelected"); $("#"+container+"Content"+(location_hash)).attr("rel",container+"ContainerSelected"); $("#"+container+"Handle"+(location_hash-1)).trigger(settings.eventTrigger); }else{ $("#"+container+"Handle"+(settings.openOnLoad)).attr("rel",container+"HandleSelected"); $("#"+container+"Content"+(settings.openOnLoad)).attr("rel",container+"ContainerSelected"); $("#"+container+"Handle"+(settings.openOnLoad-1)).trigger(settings.eventTrigger); } } }); if(settings.cycle === true){ $(this).hrzAccordionLoop(); } }); } }); })(jQuery); **Given is the code used for the accordion...please check out this Accordion Link. in the link there are four examples of accordions. i want the last accordion i.e example 4 to be vertical ...kindly help me.

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  • storing session data in mysql using php is not retrieving the data properly from the tables.

    - by Ronedog
    I have a problem retrieving some data from the $_SESSION using php and mysql. I've commented out the line in php.ini that tells the server to use the "file" to store the session info so my database will be used. I have a class that I use to write the information to the database and its working fine. When the user passes their credentials the class gets instantiated and the $_SESSION vars get set, then the user gets redirected to the index page. The index.php page includes the file where the db session class is, which when instantiated calles session_start() and the session variables should be in $_SESSION, but when I do var_dump($_SESSION) there is nothing in the array. However, when I look at the data in mysql, all the session information is in there. Its acting like session_start() has not been called, but by instantiating the class it is. Any idea what could be wrong? Here's the HTML: <?php include_once "classes/phpsessions_db/class.dbsession.php"; //used for sessions var_dump($_SESSION); ?> <html> . . . </html> Here's the dbsession class: <?php error_reporting(E_ALL); class dbSession { function dbSession($gc_maxlifetime = "", $gc_probability = "", $gc_divisor = "") { // if $gc_maxlifetime is specified and is an integer number if ($gc_maxlifetime != "" && is_integer($gc_maxlifetime)) { // set the new value @ini_set('session.gc_maxlifetime', $gc_maxlifetime); } // if $gc_probability is specified and is an integer number if ($gc_probability != "" && is_integer($gc_probability)) { // set the new value @ini_set('session.gc_probability', $gc_probability); } // if $gc_divisor is specified and is an integer number if ($gc_divisor != "" && is_integer($gc_divisor)) { // set the new value @ini_set('session.gc_divisor', $gc_divisor); } // get session lifetime $this->sessionLifetime = ini_get("session.gc_maxlifetime"); //Added by AARON. cancel the session's auto start,important, without this the session var's don't show up on next pg. session_write_close(); // register the new handler session_set_save_handler( array(&$this, 'open'), array(&$this, 'close'), array(&$this, 'read'), array(&$this, 'write'), array(&$this, 'destroy'), array(&$this, 'gc') ); register_shutdown_function('session_write_close'); // start the session @session_start(); } function stop() { $new_sess_id = $this->regenerate_id(true); session_unset(); session_destroy(); return $new_sess_id; } function regenerate_id($return_val=false) { // saves the old session's id $oldSessionID = session_id(); // regenerates the id // this function will create a new session, with a new id and containing the data from the old session // but will not delete the old session session_regenerate_id(); // because the session_regenerate_id() function does not delete the old session, // we have to delete it manually //$this->destroy($oldSessionID); //ADDED by aaron // returns the new session id if($return_val) { return session_id(); } } function open($save_path, $session_name) { // global $gf; // $gf->debug_this($gf, "GF: Opening Session"); // change the next values to match the setting of your mySQL database $mySQLHost = "localhost"; $mySQLUsername = "user"; $mySQLPassword = "pass"; $mySQLDatabase = "sessions"; $link = mysql_connect($mySQLHost, $mySQLUsername, $mySQLPassword); if (!$link) { die ("Could not connect to database!"); } $dbc = mysql_select_db($mySQLDatabase, $link); if (!$dbc) { die ("Could not select database!"); } return true; } function close() { mysql_close(); return true; } function read($session_id) { $result = @mysql_query(" SELECT session_data FROM session_data WHERE session_id = '".$session_id."' AND http_user_agent = '".$_SERVER["HTTP_USER_AGENT"]."' AND session_expire > '".time()."' "); // if anything was found if (is_resource($result) && @mysql_num_rows($result) > 0) { // return found data $fields = @mysql_fetch_assoc($result); // don't bother with the unserialization - PHP handles this automatically return unserialize($fields["session_data"]); } // if there was an error return an empty string - this HAS to be an empty string return ""; } function write($session_id, $session_data) { // global $gf; // first checks if there is a session with this id $result = @mysql_query(" SELECT * FROM session_data WHERE session_id = '".$session_id."' "); // if there is if (@mysql_num_rows($result) > 0) { // update the existing session's data // and set new expiry time $result = @mysql_query(" UPDATE session_data SET session_data = '".serialize($session_data)."', session_expire = '".(time() + $this->sessionLifetime)."' WHERE session_id = '".$session_id."' "); // if anything happened if (@mysql_affected_rows()) { // return true return true; } } else // if this session id is not in the database { // $gf->debug_this($gf, "inside dbSession, trying to write to db because session id was NOT in db"); $sql = " INSERT INTO session_data ( session_id, http_user_agent, session_data, session_expire ) VALUES ( '".serialize($session_id)."', '".$_SERVER["HTTP_USER_AGENT"]."', '".$session_data."', '".(time() + $this->sessionLifetime)."' ) "; // insert a new record $result = @mysql_query($sql); // if anything happened if (@mysql_affected_rows()) { // return an empty string return ""; } } // if something went wrong, return false return false; } function destroy($session_id) { // deletes the current session id from the database $result = @mysql_query(" DELETE FROM session_data WHERE session_id = '".$session_id."' "); // if anything happened if (@mysql_affected_rows()) { // return true return true; } // if something went wrong, return false return false; } function gc($maxlifetime) { // it deletes expired sessions from database $result = @mysql_query(" DELETE FROM session_data WHERE session_expire < '".(time() - $maxlifetime)."' "); } } //End of Class $session = new dbsession(); ?>

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  • PHP sorting issue with simpleXML

    - by tugbucket
    test.xml: <?xml version="1.0"?> <props> <prop> <state statename="Mississippi"> <info> <code>a1</code> <location>Jackson</location> </info> <info> <code>d2</code> <location>Gulfport</location> </info> <info> <code>g6</code> <location>Hattiesburg</location> </info> </state> <state statename="Texas"> <info> <code>i9</code> <location>Dallas</location> </info> <info> <code>a7</code> <location>Austin</location> </info> </state> <state statename="Maryland"> <info> <code>s5</code> <location>Mount Laurel</location> </info> <info> <code>f0</code> <location>Baltimore</location> </info> <info> <code>h4</code> <location>Annapolis</location> </info> </state> </prop> </props> test.php // start the sortCities function sortCities($a, $b){ return strcmp($a->location, $b->location); } // start the sortStates function sortStates($t1, $t2) { return strcmp($t1['statename'], $t2['statename']); } $props = simplexml_load_file('test.xml'); foreach ($props->prop as $prop) { $sortedStates = array(); foreach($prop->state as $states) { $sortedStates[] = $states; } usort($sortedStates, "sortStates"); // finish the sortStates /* --- */ echo '<pre>'."\n"; print_r($sortedStates); echo '</pre>'."\n"; /* --- */ foreach ($prop->children() as $stateattr) { // this doesn't do it //foreach($sortedStates as $hotel => @attributes){ // blargh! if(isset($stateattr->info)) { $statearr = $stateattr->attributes(); echo '<optgroup label="'.$statearr['statename'].'">'."\n"; $options = array(); foreach($stateattr->info as $info) { $options[] = $info; } usort($options, "sortCities"); // finish the sortCities foreach($options as $stateattr => $info){ echo '<option value="'.$info->code.'">'.$info->location.'</option>'."\n"; } echo '</optgroup>'."\n"; } else { //empty nodes don't do squat } } } ?> This is the array that: print_r($sortedStates); prints out: Array ( [0] => SimpleXMLElement Object ( [@attributes] => Array ( [statename] => Maryland ) [info] => Array ( [0] => SimpleXMLElement Object ( [code] => s5 [location] => Mount Laurel ) [1] => SimpleXMLElement Object ( [code] => f0 [location] => Baltimore ) [2] => SimpleXMLElement Object ( [code] => h4 [location] => Annapolis ) ) ) [1] => SimpleXMLElement Object ( [@attributes] => Array ( [statename] => Mississippi ) [info] => Array ( [0] => SimpleXMLElement Object ( [code] => a1 [location] => Jackson ) [1] => SimpleXMLElement Object ( [code] => d2 [location] => Gulfport ) [2] => SimpleXMLElement Object ( [code] => g6 [location] => Hattiesburg ) ) ) [2] => SimpleXMLElement Object ( [@attributes] => Array ( [statename] => Texas ) [info] => Array ( [0] => SimpleXMLElement Object ( [code] => i9 [location] => Dallas ) [1] => SimpleXMLElement Object ( [code] => a7 [location] => Austin ) ) ) ) this: // start the sortCities function sortCities($a, $b){ return strcmp($a->location, $b->location); } plus this part of code: $options = array(); foreach($stateattr->info as $info) { $options[] = $info; } usort($options, "sortCities"); // finish the sortCities foreach($options as $stateattr => $info){ echo '<option value="'.$info->code.'">'.$info->location.'</option>'."\n"; } is doing a fine job of sorting by the 'location' node within each optgroup. You can see that in the array I can make it sort by the attribute 'statename'. What I am having trouble with is echoing out and combining the two functions in order to have it auto sort both the states and the cities within and forming the needed optgroups. I tried copying the lines for the cities and changing the names called several ways to no avail.

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  • Creating a grid overlay over image.

    - by neteus
    Hi everybody, I made a script (using mootools library) that is supposed to overlay an image with a table grid and when each grid cell is clicked/dragged over its background color changes 'highlighting' the cell. Current code creates a table and positions it over the element (el, image in this case). Table was used since I am planning to add rectangle select tool later on, and it seemed easiest way to do it. <html> <head> <title></title> <script type="text/javascript" src="mootools.js"></script> <script type="text/javascript"> var SetGrid = function(el, sz, nr, nc){ //get number of rows/columns according to the 'grid' size numcols = el.getSize().x/sz; numrows = el.getSize().y/sz; //create table element for injecting cols/rows var gridTable = new Element('table', { 'id' : 'gridTable', 'styles' : { 'width' : el.getSize().x, 'height' : el.getSize().y, 'top' : el.getCoordinates().top, 'left' : el.getCoordinates().left } }); //inject rows/cols into gridTable for (row = 1; row<=numrows; row++){ thisRow = new Element('tr', { 'id' : row, 'class' : 'gridRow' }); for(col = 1; col<=numcols; col++){ thisCol = new Element('td', { 'id' : col, 'class' : 'gridCol0' }); //each cell gets down/up over event... down starts dragging|up stops|over draws area if down was fired thisCol.addEvents({ 'mousedown' : function(){ dragFlag = true; startRow = this.getParent().get('id'); startCol = this.get('id'); }, 'mouseup' : function(){ dragFlag = false; }, 'mouseover' : function(){ if (dragFlag==true){ this.set('class', 'gridCol'+$$('#lvlSelect .on').get('value')); } }, 'click' : function(){ //this.set('class', 'gridCol'+$$('#lvlSelect .on').get('id').substr(3, 1) ); str = $$('#lvlSelect .on').get('id'); alert(str.substr(2, 3)); } }); thisCol.inject(thisRow, 'bottom'); }; thisRow.inject(gridTable, 'bottom'); }; gridTable.inject(el.getParent()); } //sens level selector func var SetSensitivitySelector = function(el, sz, nr, nc){ $$('#lvlSelect ul li').each(function(el){ el.addEvents({ 'click' : function(){ $$('#lvlSelect ul li').set('class', ''); this.set('class', 'on'); }, 'mouseover' : function(){ el.setStyle('cursor','pointer'); }, 'mouseout' : function(){ el.setStyle('cursor',''); } }); }); } //execute window.addEvent('load', function(){ SetGrid($('imagetomap'), 32); SetSensitivitySelector(); }); </script> <style> #imagetomapdiv { float:left; display: block; } #gridTable { border:1px solid red; border-collapse:collapse; position:absolute; z-index:5; } #gridTable td { opacity:0.2; filter:alpha(opacity=20); } #gridTable .gridCol0 { border:1px solid gray; background-color: none; } #gridTable .gridCol1 { border:1px solid gray; background-color: green; } #gridTable .gridCol2 { border:1px solid gray; background-color: blue; } #gridTable .gridCol3 { border:1px solid gray; background-color: yellow; } #gridTable .gridCol4 { border:1px solid gray; background-color: orange; } #gridTable .gridCol5 { border:1px solid gray; background-color: red; } #lvlSelect ul {float: left; display:block; position:relative; margin-left: 20px; padding: 10px; } #lvlSelect ul li { width:40px; text-align:center; display:block; border:1px solid black; position:relative; padding: 10px; list-style:none; opacity:0.2; filter:alpha(opacity=20); } #lvlSelect ul li.on { opacity:1; filter:alpha(opacity=100); } #lvlSelect ul #li0 { background-color: none; } #lvlSelect ul #li1 { background-color: green; } #lvlSelect ul #li2 { background-color: blue; } #lvlSelect ul #li3 { background-color: yellow; } #lvlSelect ul #li4 { background-color: orange; } #lvlSelect ul #li5 { background-color: red; } </style> </head> <body> <div id="imagetomapdiv"> <img id="imagetomap" src="1.png"> </div> <div id="lvlSelect"> <ul> <li value="0" id="li0">0</li> <li value="1" id="li1">1</li> <li value="2" id="li2">2</li> <li value="3" id="li3">3</li> <li value="4" id="li4">4</li> <li value="5" id="li5" class="on">5</li> </ul> </div> </body> </html> A 'working' example: http://72.14.186.218/~alex/motion.php There are two problems: while it works just fine in FF, IE and Chrome do not create the table if the page is refreshed. If you go back to directory root and click on the link to the file the grid table is displayed, if you hit 'refresh' button -- the script runs but the table is not injected. Secondly, although the table HTML is injected in IE, it does not display it. I tried adding nbsp's to make sure its not ignored -- to no avail. Any suggestions on improving code or help with the issues is appreciated. Thanks!

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  • Backbone events not firing (this.el undefined) & general feedback on use of the framework

    - by Leo
    I am very new to backbone.js and I am struggling a little. I figured out a way to get data from the server (in json) onto the screen successfully but am I doing it the right/best way? I know there is something wrong because the only view which contains a valid this.el is the parent view. I suspect that because of this, the events of the view are not firing ()... What is the best way forward? Here is the code: var surveyUrl = "/api/Survey?format=json&callback=?"; $(function () { AnswerOption = Backbone.Model.extend({}); AnswerOptionList = Backbone.Collection.extend({ initialize: function (models, options) { this.bind("add", options.view.render); } }); AnswerOptionView = Backbone.View.extend({ initialize: function () { this.answerOptionList = new AnswerOptionList(null, { view: this }); _.bindAll(this, 'render'); }, events: { "click .answerOptionControl": "updateCheckedState" //does not fire because there is no this.el }, render: function (model) { // Compile the template using underscore var template = _.template($("#questionAnswerOptionTemplate").html(), model.answerOption); $('#answerOptions' + model.answerOption.questionId + '>fieldset').append(template); return this; }, updateCheckedState: function (data) { //never hit... } }); Question = Backbone.Model.extend({}); QuestionList = Backbone.Collection.extend({ initialize: function (models, options) { this.bind("add", options.view.render); } }); QuestionView = Backbone.View.extend({ initialize: function () { this.questionlist = new QuestionList(null, { view: this }); _.bindAll(this, 'render'); }, render: function (model) { // Compile the template using underscore var template = _.template($("#questionTemplate").html(), model.question); $("#questions").append(template); //append answers using AnswerOptionView var view = new AnswerOptionView(); for (var i = 0; i < model.question.answerOptions.length; i++) { var qModel = new AnswerOption(); qModel.answerOption = model.question.answerOptions[i]; qModel.questionChoiceType = ChoiceType(); view.answerOptionList.add(qModel); } $('#questions').trigger('create'); return this; } }); Survey = Backbone.Model.extend({ url: function () { return this.get("id") ? surveyUrl + '/' + this.get("id") : surveyUrl; } }); SurveyList = Backbone.Collection.extend({ model: Survey, url: surveyUrl }); aSurvey = new Survey({ Id: 1 }); SurveyView = Backbone.View.extend({ model: aSurvey, initialize: function () { _.bindAll(this, 'render'); this.model.bind('refresh', this.render); this.model.bind('change', this.render); this.model.view = this; }, // Re-render the contents render: function () { var view = new QuestionView(); //{el:this.el}); for (var i = 0; i < this.model.attributes[0].questions.length; i++) { var qModel = new Question(); qModel.question = this.model.attributes[0].questions[i]; view.questionlist.add(qModel); } } }); window.App = new SurveyView(aSurvey); aSurvey.fetch(); }); -html <body> <div id="questions"></div> <!-- Templates --> <script type="text/template" id="questionAnswerOptionTemplate"> <input name="answerOptionGroup<%= questionId %>" id="answerOptionInput<%= id %>" type="checkbox" class="answerOptionControl"/> <label for="answerOptionInput<%= id %>"><%= text %></label> </script> <script type="text/template" id="questionTemplate"> <div id="question<%=id %>" class="questionWithCurve"> <h1><%= headerText %></h1> <h2><%= subText %></h2> <div data-role="fieldcontain" id="answerOptions<%= id %>" > <fieldset data-role="controlgroup" data-type="vertical"> <legend> </legend> </fieldset> </div> </div> </script> </body> And the JSON from the server: ? ({ "name": "Survey", "questions": [{ "surveyId": 1, "headerText": "Question 1", "subText": "subtext", "type": "Choice", "positionOrder": 1, "answerOptions": [{ "questionId": 1, "text": "Question 1 - Option 1", "positionOrder": 1, "id": 1, "createdOn": "\/Date(1333666034297+0100)\/" }, { "questionId": 1, "text": "Question 1 - Option 2", "positionOrder": 2, "id": 2, "createdOn": "\/Date(1333666034340+0100)\/" }, { "questionId": 1, "text": "Question 1 - Option 3", "positionOrder": 3, "id": 3, "createdOn": "\/Date(1333666034350+0100)\/" }], "questionValidators": [{ "questionId": 1, "value": "3", "type": "MaxAnswers", "id": 1, "createdOn": "\/Date(1333666034267+0100)\/" }, { "questionId": 1, "value": "1", "type": "MinAnswers", "id": 2, "createdOn": "\/Date(1333666034283+0100)\/" }], "id": 1, "createdOn": "\/Date(1333666034257+0100)\/" }, { "surveyId": 1, "headerText": "Question 2", "subText": "subtext", "type": "Choice", "positionOrder": 2, "answerOptions": [{ "questionId": 2, "text": "Question 2 - Option 1", "positionOrder": 1, "id": 4, "createdOn": "\/Date(1333666034427+0100)\/" }, { "questionId": 2, "text": "Question 2 - Option 2", "positionOrder": 2, "id": 5, "createdOn": "\/Date(1333666034440+0100)\/" }, { "questionId": 2, "text": "Question 2 - Option 3", "positionOrder": 3, "id": 6, "createdOn": "\/Date(1333666034447+0100)\/" }], "questionValidators": [{ "questionId": 2, "value": "3", "type": "MaxAnswers", "id": 3, "createdOn": "\/Date(1333666034407+0100)\/" }, { "questionId": 2, "value": "1", "type": "MinAnswers", "id": 4, "createdOn": "\/Date(1333666034417+0100)\/" }], "id": 2, "createdOn": "\/Date(1333666034377+0100)\/" }, { "surveyId": 1, "headerText": "Question 3", "subText": "subtext", "type": "Choice", "positionOrder": 3, "answerOptions": [{ "questionId": 3, "text": "Question 3 - Option 1", "positionOrder": 1, "id": 7, "createdOn": "\/Date(1333666034477+0100)\/" }, { "questionId": 3, "text": "Question 3 - Option 2", "positionOrder": 2, "id": 8, "createdOn": "\/Date(1333666034483+0100)\/" }, { "questionId": 3, "text": "Question 3 - Option 3", "positionOrder": 3, "id": 9, "createdOn": "\/Date(1333666034487+0100)\/" }], "questionValidators": [{ "questionId": 3, "value": "3", "type": "MaxAnswers", "id": 5, "createdOn": "\/Date(1333666034463+0100)\/" }, { "questionId": 3, "value": "1", "type": "MinAnswers", "id": 6, "createdOn": "\/Date(1333666034470+0100)\/" }], "id": 3, "createdOn": "\/Date(1333666034457+0100)\/" }, { "surveyId": 1, "headerText": "Question 4", "subText": "subtext", "type": "Choice", "positionOrder": 4, "answerOptions": [{ "questionId": 4, "text": "Question 4 - Option 1", "positionOrder": 1, "id": 10, "createdOn": "\/Date(1333666034500+0100)\/" }, { "questionId": 4, "text": "Question 4 - Option 2", "positionOrder": 2, "id": 11, "createdOn": "\/Date(1333666034507+0100)\/" }, { "questionId": 4, "text": "Question 4 - Option 3", "positionOrder": 3, "id": 12, "createdOn": "\/Date(1333666034507+0100)\/" }], "questionValidators": [{ "questionId": 4, "value": "3", "type": "MaxAnswers", "id": 7, "createdOn": "\/Date(1333666034493+0100)\/" }, { "questionId": 4, "value": "1", "type": "MinAnswers", "id": 8, "createdOn": "\/Date(1333666034497+0100)\/" }], "id": 4, "createdOn": "\/Date(1333666034490+0100)\/" }], "id": 1, "createdOn": "\/Date(1333666034243+0100)\/" })

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  • C# 4.0: COM Interop Improvements

    - by Paulo Morgado
    Dynamic resolution as well as named and optional arguments greatly improve the experience of interoperating with COM APIs such as Office Automation Primary Interop Assemblies (PIAs). But, in order to alleviate even more COM Interop development, a few COM-specific features were also added to C# 4.0. Ommiting ref Because of a different programming model, many COM APIs contain a lot of reference parameters. These parameters are typically not meant to mutate a passed-in argument, but are simply another way of passing value parameters. Specifically for COM methods, the compiler allows to declare the method call passing the arguments by value and will automatically generate the necessary temporary variables to hold the values in order to pass them by reference and will discard their values after the call returns. From the point of view of the programmer, the arguments are being passed by value. This method call: object fileName = "Test.docx"; object missing = Missing.Value; document.SaveAs(ref fileName, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing); can now be written like this: document.SaveAs("Test.docx", Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value); And because all parameters that are receiving the Missing.Value value have that value as its default value, the declaration of the method call can even be reduced to this: document.SaveAs("Test.docx"); Dynamic Import Many COM methods accept and return variant types, which are represented in the PIAs as object. In the vast majority of cases, a programmer calling these methods already knows the static type of a returned object form the context of the call, but has to explicitly perform a cast on the returned values to make use of that knowledge. These casts are so common that they constitute a major nuisance. To make the developer’s life easier, it is now possible to import the COM APIs in such a way that variants are instead represented using the type dynamic which means that COM signatures have now occurrences of dynamic instead of object. This means that members of a returned object can now be easily accessed or assigned into a strongly typed variable without having to cast. Instead of this code: ((Excel.Range)(excel.Cells[1, 1])).Value2 = "Hello World!"; this code can now be used: excel.Cells[1, 1] = "Hello World!"; And instead of this: Excel.Range range = (Excel.Range)(excel.Cells[1, 1]); this can be used: Excel.Range range = excel.Cells[1, 1]; Indexed And Default Properties A few COM interface features are still not available in C#. On the top of the list are indexed properties and default properties. As mentioned above, these will be possible if the COM interface is accessed dynamically, but will not be recognized by statically typed C# code. No PIAs – Type Equivalence And Type Embedding For assemblies indentified with PrimaryInteropAssemblyAttribute, the compiler will create equivalent types (interfaces, structs, enumerations and delegates) and embed them in the generated assembly. To reduce the final size of the generated assembly, only the used types and their used members will be generated and embedded. Although this makes development and deployment of applications using the COM components easier because there’s no need to deploy the PIAs, COM component developers are still required to build the PIAs.

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  • JDBC Triggers

    - by Tim Dexter
    Received a question from a customer last week, they were using the new rollup patch on top of 10.1.3.4.1. What are these boxes for? Don't you know? Surely? Well, they are for ... that new functionality, you know it's in the user docs, that thingmabobby doodah. OK, I dont know either, I can have a guess but let me check first. Serveral IM sessions, emails and a dig through the readme for the new patch and I had my answer. Its not in the official documentation, yet. Leslie is on the case. The two fields were designed to allow an Admin to set a users context attributes before a connection is made to a database and for un-setting the attributes after the connection is broken by the extraction engine. We got a sample from the Enterprise Manager team on how they will be using it with their VPD connections. FUNCTION bip_to_em_user (user_name_in IN VARCHAR2) RETURN BOOLEAN IS BEGIN SETEMUSERCONTEXT(user_name_in, MGMT_USER.OP_SET_IDENTIFIER); return TRUE; END bip_to_em_user; And used in the jdbc data source definition like this (pre-process function): sysman.mgmt_bip.bip_to_em_user(:xdo_user_name) You, of course can call any function that is going to return a boolean value, another example might be. FUNCTION set_per_process_username (username_in IN VARCHAR2) RETURN BOOLEAN IS BEGIN SETUSERCONTEXT(username_in); return TRUE; END set_per_process_username Just use your own function/package to set some user context. Very grateful for the mail from Leslie on the EM team's usage but I had to try it out. Rather than set up a VPD, I opted for a simpler test. Can I log the comings and goings of users and their queries using the same pre-process text box. Reaching back into the depths of my developer brain to remember some pl/sql, it was not that deep and I came up with: CREATE OR REPLACE FUNCTION BIPTEST (user_name_in IN VARCHAR2, smode IN VARCHAR2) RETURN BOOLEAN AS BEGIN INSERT INTO LOGTAB VALUES(user_name_in, sysdate,smode); RETURN true; END BIPTEST; To call it in the pre-fetch trigger. BIPTEST(:xdo_user_name) Not going to set the pl/sql world alight I know, but you get the idea. As a new connection is made to the database its logged in the LOGTAB table. The SMODE value just sets if its an entry or an exit. I used the pre- and post- boxes. NAME UPDATE_DATE S_FLAG oracle 14-MAY-10 09.51.34.000000000 AM Start oracle 14-MAY-10 10.23.57.000000000 AM Finish administrator 14-MAY-10 09.51.38.000000000 AM Start administrator 14-MAY-10 09.51.38.000000000 AM Finish oracle 14-MAY-10 09.51.42.000000000 AM Start oracle 14-MAY-10 09.51.42.000000000 AM Finish It works very well, I had some fun trying to find a nasty query for the extraction engine so that the timestamps from in to out actually had a difference. That engine is fast! The only derived value you can pass from BIP is :xdo_user_name. None of the other server values are available. Connection pools are not currently supported but planned for a future release. Now you know what those fields are for and look for some official documentation, rather than my ramblings, coming soon!

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  • How John Got 15x Improvement Without Really Trying

    - by rchrd
    The following article was published on a Sun Microsystems website a number of years ago by John Feo. It is still useful and worth preserving. So I'm republishing it here.  How I Got 15x Improvement Without Really Trying John Feo, Sun Microsystems Taking ten "personal" program codes used in scientific and engineering research, the author was able to get from 2 to 15 times performance improvement easily by applying some simple general optimization techniques. Introduction Scientific research based on computer simulation depends on the simulation for advancement. The research can advance only as fast as the computational codes can execute. The codes' efficiency determines both the rate and quality of results. In the same amount of time, a faster program can generate more results and can carry out a more detailed simulation of physical phenomena than a slower program. Highly optimized programs help science advance quickly and insure that monies supporting scientific research are used as effectively as possible. Scientific computer codes divide into three broad categories: ISV, community, and personal. ISV codes are large, mature production codes developed and sold commercially. The codes improve slowly over time both in methods and capabilities, and they are well tuned for most vendor platforms. Since the codes are mature and complex, there are few opportunities to improve their performance solely through code optimization. Improvements of 10% to 15% are typical. Examples of ISV codes are DYNA3D, Gaussian, and Nastran. Community codes are non-commercial production codes used by a particular research field. Generally, they are developed and distributed by a single academic or research institution with assistance from the community. Most users just run the codes, but some develop new methods and extensions that feed back into the general release. The codes are available on most vendor platforms. Since these codes are younger than ISV codes, there are more opportunities to optimize the source code. Improvements of 50% are not unusual. Examples of community codes are AMBER, CHARM, BLAST, and FASTA. Personal codes are those written by single users or small research groups for their own use. These codes are not distributed, but may be passed from professor-to-student or student-to-student over several years. They form the primordial ocean of applications from which community and ISV codes emerge. Government research grants pay for the development of most personal codes. This paper reports on the nature and performance of this class of codes. Over the last year, I have looked at over two dozen personal codes from more than a dozen research institutions. The codes cover a variety of scientific fields, including astronomy, atmospheric sciences, bioinformatics, biology, chemistry, geology, and physics. The sources range from a few hundred lines to more than ten thousand lines, and are written in Fortran, Fortran 90, C, and C++. For the most part, the codes are modular, documented, and written in a clear, straightforward manner. They do not use complex language features, advanced data structures, programming tricks, or libraries. I had little trouble understanding what the codes did or how data structures were used. Most came with a makefile. Surprisingly, only one of the applications is parallel. All developers have access to parallel machines, so availability is not an issue. Several tried to parallelize their applications, but stopped after encountering difficulties. Lack of education and a perception that parallelism is difficult prevented most from trying. I parallelized several of the codes using OpenMP, and did not judge any of the codes as difficult to parallelize. Even more surprising than the lack of parallelism is the inefficiency of the codes. I was able to get large improvements in performance in a matter of a few days applying simple optimization techniques. Table 1 lists ten representative codes [names and affiliation are omitted to preserve anonymity]. Improvements on one processor range from 2x to 15.5x with a simple average of 4.75x. I did not use sophisticated performance tools or drill deep into the program's execution character as one would do when tuning ISV or community codes. Using only a profiler and source line timers, I identified inefficient sections of code and improved their performance by inspection. The changes were at a high level. I am sure there is another factor of 2 or 3 in each code, and more if the codes are parallelized. The study’s results show that personal scientific codes are running many times slower than they should and that the problem is pervasive. Computational scientists are not sloppy programmers; however, few are trained in the art of computer programming or code optimization. I found that most have a working knowledge of some programming language and standard software engineering practices; but they do not know, or think about, how to make their programs run faster. They simply do not know the standard techniques used to make codes run faster. In fact, they do not even perceive that such techniques exist. The case studies described in this paper show that applying simple, well known techniques can significantly increase the performance of personal codes. It is important that the scientific community and the Government agencies that support scientific research find ways to better educate academic scientific programmers. The inefficiency of their codes is so bad that it is retarding both the quality and progress of scientific research. # cacheperformance redundantoperations loopstructures performanceimprovement 1 x x 15.5 2 x 2.8 3 x x 2.5 4 x 2.1 5 x x 2.0 6 x 5.0 7 x 5.8 8 x 6.3 9 2.2 10 x x 3.3 Table 1 — Area of improvement and performance gains of 10 codes The remainder of the paper is organized as follows: sections 2, 3, and 4 discuss the three most common sources of inefficiencies in the codes studied. These are cache performance, redundant operations, and loop structures. Each section includes several examples. The last section summaries the work and suggests a possible solution to the issues raised. Optimizing cache performance Commodity microprocessor systems use caches to increase memory bandwidth and reduce memory latencies. Typical latencies from processor to L1, L2, local, and remote memory are 3, 10, 50, and 200 cycles, respectively. Moreover, bandwidth falls off dramatically as memory distances increase. Programs that do not use cache effectively run many times slower than programs that do. When optimizing for cache, the biggest performance gains are achieved by accessing data in cache order and reusing data to amortize the overhead of cache misses. Secondary considerations are prefetching, associativity, and replacement; however, the understanding and analysis required to optimize for the latter are probably beyond the capabilities of the non-expert. Much can be gained simply by accessing data in the correct order and maximizing data reuse. 6 out of the 10 codes studied here benefited from such high level optimizations. Array Accesses The most important cache optimization is the most basic: accessing Fortran array elements in column order and C array elements in row order. Four of the ten codes—1, 2, 4, and 10—got it wrong. Compilers will restructure nested loops to optimize cache performance, but may not do so if the loop structure is too complex, or the loop body includes conditionals, complex addressing, or function calls. In code 1, the compiler failed to invert a key loop because of complex addressing do I = 0, 1010, delta_x IM = I - delta_x IP = I + delta_x do J = 5, 995, delta_x JM = J - delta_x JP = J + delta_x T1 = CA1(IP, J) + CA1(I, JP) T2 = CA1(IM, J) + CA1(I, JM) S1 = T1 + T2 - 4 * CA1(I, J) CA(I, J) = CA1(I, J) + D * S1 end do end do In code 2, the culprit is conditionals do I = 1, N do J = 1, N If (IFLAG(I,J) .EQ. 0) then T1 = Value(I, J-1) T2 = Value(I-1, J) T3 = Value(I, J) T4 = Value(I+1, J) T5 = Value(I, J+1) Value(I,J) = 0.25 * (T1 + T2 + T5 + T4) Delta = ABS(T3 - Value(I,J)) If (Delta .GT. MaxDelta) MaxDelta = Delta endif enddo enddo I fixed both programs by inverting the loops by hand. Code 10 has three-dimensional arrays and triply nested loops. The structure of the most computationally intensive loops is too complex to invert automatically or by hand. The only practical solution is to transpose the arrays so that the dimension accessed by the innermost loop is in cache order. The arrays can be transposed at construction or prior to entering a computationally intensive section of code. The former requires all array references to be modified, while the latter is cost effective only if the cost of the transpose is amortized over many accesses. I used the second approach to optimize code 10. Code 5 has four-dimensional arrays and loops are nested four deep. For all of the reasons cited above the compiler is not able to restructure three key loops. Assume C arrays and let the four dimensions of the arrays be i, j, k, and l. In the original code, the index structure of the three loops is L1: for i L2: for i L3: for i for l for l for j for k for j for k for j for k for l So only L3 accesses array elements in cache order. L1 is a very complex loop—much too complex to invert. I brought the loop into cache alignment by transposing the second and fourth dimensions of the arrays. Since the code uses a macro to compute all array indexes, I effected the transpose at construction and changed the macro appropriately. The dimensions of the new arrays are now: i, l, k, and j. L3 is a simple loop and easily inverted. L2 has a loop-carried scalar dependence in k. By promoting the scalar name that carries the dependence to an array, I was able to invert the third and fourth subloops aligning the loop with cache. Code 5 is by far the most difficult of the four codes to optimize for array accesses; but the knowledge required to fix the problems is no more than that required for the other codes. I would judge this code at the limits of, but not beyond, the capabilities of appropriately trained computational scientists. Array Strides When a cache miss occurs, a line (64 bytes) rather than just one word is loaded into the cache. If data is accessed stride 1, than the cost of the miss is amortized over 8 words. Any stride other than one reduces the cost savings. Two of the ten codes studied suffered from non-unit strides. The codes represent two important classes of "strided" codes. Code 1 employs a multi-grid algorithm to reduce time to convergence. The grids are every tenth, fifth, second, and unit element. Since time to convergence is inversely proportional to the distance between elements, coarse grids converge quickly providing good starting values for finer grids. The better starting values further reduce the time to convergence. The downside is that grids of every nth element, n > 1, introduce non-unit strides into the computation. In the original code, much of the savings of the multi-grid algorithm were lost due to this problem. I eliminated the problem by compressing (copying) coarse grids into continuous memory, and rewriting the computation as a function of the compressed grid. On convergence, I copied the final values of the compressed grid back to the original grid. The savings gained from unit stride access of the compressed grid more than paid for the cost of copying. Using compressed grids, the loop from code 1 included in the previous section becomes do j = 1, GZ do i = 1, GZ T1 = CA(i+0, j-1) + CA(i-1, j+0) T4 = CA1(i+1, j+0) + CA1(i+0, j+1) S1 = T1 + T4 - 4 * CA1(i+0, j+0) CA(i+0, j+0) = CA1(i+0, j+0) + DD * S1 enddo enddo where CA and CA1 are compressed arrays of size GZ. Code 7 traverses a list of objects selecting objects for later processing. The labels of the selected objects are stored in an array. The selection step has unit stride, but the processing steps have irregular stride. A fix is to save the parameters of the selected objects in temporary arrays as they are selected, and pass the temporary arrays to the processing functions. The fix is practical if the same parameters are used in selection as in processing, or if processing comprises a series of distinct steps which use overlapping subsets of the parameters. Both conditions are true for code 7, so I achieved significant improvement by copying parameters to temporary arrays during selection. Data reuse In the previous sections, we optimized for spatial locality. It is also important to optimize for temporal locality. Once read, a datum should be used as much as possible before it is forced from cache. Loop fusion and loop unrolling are two techniques that increase temporal locality. Unfortunately, both techniques increase register pressure—as loop bodies become larger, the number of registers required to hold temporary values grows. Once register spilling occurs, any gains evaporate quickly. For multiprocessors with small register sets or small caches, the sweet spot can be very small. In the ten codes presented here, I found no opportunities for loop fusion and only two opportunities for loop unrolling (codes 1 and 3). In code 1, unrolling the outer and inner loop one iteration increases the number of result values computed by the loop body from 1 to 4, do J = 1, GZ-2, 2 do I = 1, GZ-2, 2 T1 = CA1(i+0, j-1) + CA1(i-1, j+0) T2 = CA1(i+1, j-1) + CA1(i+0, j+0) T3 = CA1(i+0, j+0) + CA1(i-1, j+1) T4 = CA1(i+1, j+0) + CA1(i+0, j+1) T5 = CA1(i+2, j+0) + CA1(i+1, j+1) T6 = CA1(i+1, j+1) + CA1(i+0, j+2) T7 = CA1(i+2, j+1) + CA1(i+1, j+2) S1 = T1 + T4 - 4 * CA1(i+0, j+0) S2 = T2 + T5 - 4 * CA1(i+1, j+0) S3 = T3 + T6 - 4 * CA1(i+0, j+1) S4 = T4 + T7 - 4 * CA1(i+1, j+1) CA(i+0, j+0) = CA1(i+0, j+0) + DD * S1 CA(i+1, j+0) = CA1(i+1, j+0) + DD * S2 CA(i+0, j+1) = CA1(i+0, j+1) + DD * S3 CA(i+1, j+1) = CA1(i+1, j+1) + DD * S4 enddo enddo The loop body executes 12 reads, whereas as the rolled loop shown in the previous section executes 20 reads to compute the same four values. In code 3, two loops are unrolled 8 times and one loop is unrolled 4 times. Here is the before for (k = 0; k < NK[u]; k++) { sum = 0.0; for (y = 0; y < NY; y++) { sum += W[y][u][k] * delta[y]; } backprop[i++]=sum; } and after code for (k = 0; k < KK - 8; k+=8) { sum0 = 0.0; sum1 = 0.0; sum2 = 0.0; sum3 = 0.0; sum4 = 0.0; sum5 = 0.0; sum6 = 0.0; sum7 = 0.0; for (y = 0; y < NY; y++) { sum0 += W[y][0][k+0] * delta[y]; sum1 += W[y][0][k+1] * delta[y]; sum2 += W[y][0][k+2] * delta[y]; sum3 += W[y][0][k+3] * delta[y]; sum4 += W[y][0][k+4] * delta[y]; sum5 += W[y][0][k+5] * delta[y]; sum6 += W[y][0][k+6] * delta[y]; sum7 += W[y][0][k+7] * delta[y]; } backprop[k+0] = sum0; backprop[k+1] = sum1; backprop[k+2] = sum2; backprop[k+3] = sum3; backprop[k+4] = sum4; backprop[k+5] = sum5; backprop[k+6] = sum6; backprop[k+7] = sum7; } for one of the loops unrolled 8 times. Optimizing for temporal locality is the most difficult optimization considered in this paper. The concepts are not difficult, but the sweet spot is small. Identifying where the program can benefit from loop unrolling or loop fusion is not trivial. Moreover, it takes some effort to get it right. Still, educating scientific programmers about temporal locality and teaching them how to optimize for it will pay dividends. Reducing instruction count Execution time is a function of instruction count. Reduce the count and you usually reduce the time. The best solution is to use a more efficient algorithm; that is, an algorithm whose order of complexity is smaller, that converges quicker, or is more accurate. Optimizing source code without changing the algorithm yields smaller, but still significant, gains. This paper considers only the latter because the intent is to study how much better codes can run if written by programmers schooled in basic code optimization techniques. The ten codes studied benefited from three types of "instruction reducing" optimizations. The two most prevalent were hoisting invariant memory and data operations out of inner loops. The third was eliminating unnecessary data copying. The nature of these inefficiencies is language dependent. Memory operations The semantics of C make it difficult for the compiler to determine all the invariant memory operations in a loop. The problem is particularly acute for loops in functions since the compiler may not know the values of the function's parameters at every call site when compiling the function. Most compilers support pragmas to help resolve ambiguities; however, these pragmas are not comprehensive and there is no standard syntax. To guarantee that invariant memory operations are not executed repetitively, the user has little choice but to hoist the operations by hand. The problem is not as severe in Fortran programs because in the absence of equivalence statements, it is a violation of the language's semantics for two names to share memory. Codes 3 and 5 are C programs. In both cases, the compiler did not hoist all invariant memory operations from inner loops. Consider the following loop from code 3 for (y = 0; y < NY; y++) { i = 0; for (u = 0; u < NU; u++) { for (k = 0; k < NK[u]; k++) { dW[y][u][k] += delta[y] * I1[i++]; } } } Since dW[y][u] can point to the same memory space as delta for one or more values of y and u, assignment to dW[y][u][k] may change the value of delta[y]. In reality, dW and delta do not overlap in memory, so I rewrote the loop as for (y = 0; y < NY; y++) { i = 0; Dy = delta[y]; for (u = 0; u < NU; u++) { for (k = 0; k < NK[u]; k++) { dW[y][u][k] += Dy * I1[i++]; } } } Failure to hoist invariant memory operations may be due to complex address calculations. If the compiler can not determine that the address calculation is invariant, then it can hoist neither the calculation nor the associated memory operations. As noted above, code 5 uses a macro to address four-dimensional arrays #define MAT4D(a,q,i,j,k) (double *)((a)->data + (q)*(a)->strides[0] + (i)*(a)->strides[3] + (j)*(a)->strides[2] + (k)*(a)->strides[1]) The macro is too complex for the compiler to understand and so, it does not identify any subexpressions as loop invariant. The simplest way to eliminate the address calculation from the innermost loop (over i) is to define a0 = MAT4D(a,q,0,j,k) before the loop and then replace all instances of *MAT4D(a,q,i,j,k) in the loop with a0[i] A similar problem appears in code 6, a Fortran program. The key loop in this program is do n1 = 1, nh nx1 = (n1 - 1) / nz + 1 nz1 = n1 - nz * (nx1 - 1) do n2 = 1, nh nx2 = (n2 - 1) / nz + 1 nz2 = n2 - nz * (nx2 - 1) ndx = nx2 - nx1 ndy = nz2 - nz1 gxx = grn(1,ndx,ndy) gyy = grn(2,ndx,ndy) gxy = grn(3,ndx,ndy) balance(n1,1) = balance(n1,1) + (force(n2,1) * gxx + force(n2,2) * gxy) * h1 balance(n1,2) = balance(n1,2) + (force(n2,1) * gxy + force(n2,2) * gyy)*h1 end do end do The programmer has written this loop well—there are no loop invariant operations with respect to n1 and n2. However, the loop resides within an iterative loop over time and the index calculations are independent with respect to time. Trading space for time, I precomputed the index values prior to the entering the time loop and stored the values in two arrays. I then replaced the index calculations with reads of the arrays. Data operations Ways to reduce data operations can appear in many forms. Implementing a more efficient algorithm produces the biggest gains. The closest I came to an algorithm change was in code 4. This code computes the inner product of K-vectors A(i) and B(j), 0 = i < N, 0 = j < M, for most values of i and j. Since the program computes most of the NM possible inner products, it is more efficient to compute all the inner products in one triply-nested loop rather than one at a time when needed. The savings accrue from reading A(i) once for all B(j) vectors and from loop unrolling. for (i = 0; i < N; i+=8) { for (j = 0; j < M; j++) { sum0 = 0.0; sum1 = 0.0; sum2 = 0.0; sum3 = 0.0; sum4 = 0.0; sum5 = 0.0; sum6 = 0.0; sum7 = 0.0; for (k = 0; k < K; k++) { sum0 += A[i+0][k] * B[j][k]; sum1 += A[i+1][k] * B[j][k]; sum2 += A[i+2][k] * B[j][k]; sum3 += A[i+3][k] * B[j][k]; sum4 += A[i+4][k] * B[j][k]; sum5 += A[i+5][k] * B[j][k]; sum6 += A[i+6][k] * B[j][k]; sum7 += A[i+7][k] * B[j][k]; } C[i+0][j] = sum0; C[i+1][j] = sum1; C[i+2][j] = sum2; C[i+3][j] = sum3; C[i+4][j] = sum4; C[i+5][j] = sum5; C[i+6][j] = sum6; C[i+7][j] = sum7; }} This change requires knowledge of a typical run; i.e., that most inner products are computed. The reasons for the change, however, derive from basic optimization concepts. It is the type of change easily made at development time by a knowledgeable programmer. In code 5, we have the data version of the index optimization in code 6. Here a very expensive computation is a function of the loop indices and so cannot be hoisted out of the loop; however, the computation is invariant with respect to an outer iterative loop over time. We can compute its value for each iteration of the computation loop prior to entering the time loop and save the values in an array. The increase in memory required to store the values is small in comparison to the large savings in time. The main loop in Code 8 is doubly nested. The inner loop includes a series of guarded computations; some are a function of the inner loop index but not the outer loop index while others are a function of the outer loop index but not the inner loop index for (j = 0; j < N; j++) { for (i = 0; i < M; i++) { r = i * hrmax; R = A[j]; temp = (PRM[3] == 0.0) ? 1.0 : pow(r, PRM[3]); high = temp * kcoeff * B[j] * PRM[2] * PRM[4]; low = high * PRM[6] * PRM[6] / (1.0 + pow(PRM[4] * PRM[6], 2.0)); kap = (R > PRM[6]) ? high * R * R / (1.0 + pow(PRM[4]*r, 2.0) : low * pow(R/PRM[6], PRM[5]); < rest of loop omitted > }} Note that the value of temp is invariant to j. Thus, we can hoist the computation for temp out of the loop and save its values in an array. for (i = 0; i < M; i++) { r = i * hrmax; TEMP[i] = pow(r, PRM[3]); } [N.B. – the case for PRM[3] = 0 is omitted and will be reintroduced later.] We now hoist out of the inner loop the computations invariant to i. Since the conditional guarding the value of kap is invariant to i, it behooves us to hoist the computation out of the inner loop, thereby executing the guard once rather than M times. The final version of the code is for (j = 0; j < N; j++) { R = rig[j] / 1000.; tmp1 = kcoeff * par[2] * beta[j] * par[4]; tmp2 = 1.0 + (par[4] * par[4] * par[6] * par[6]); tmp3 = 1.0 + (par[4] * par[4] * R * R); tmp4 = par[6] * par[6] / tmp2; tmp5 = R * R / tmp3; tmp6 = pow(R / par[6], par[5]); if ((par[3] == 0.0) && (R > par[6])) { for (i = 1; i <= imax1; i++) KAP[i] = tmp1 * tmp5; } else if ((par[3] == 0.0) && (R <= par[6])) { for (i = 1; i <= imax1; i++) KAP[i] = tmp1 * tmp4 * tmp6; } else if ((par[3] != 0.0) && (R > par[6])) { for (i = 1; i <= imax1; i++) KAP[i] = tmp1 * TEMP[i] * tmp5; } else if ((par[3] != 0.0) && (R <= par[6])) { for (i = 1; i <= imax1; i++) KAP[i] = tmp1 * TEMP[i] * tmp4 * tmp6; } for (i = 0; i < M; i++) { kap = KAP[i]; r = i * hrmax; < rest of loop omitted > } } Maybe not the prettiest piece of code, but certainly much more efficient than the original loop, Copy operations Several programs unnecessarily copy data from one data structure to another. This problem occurs in both Fortran and C programs, although it manifests itself differently in the two languages. Code 1 declares two arrays—one for old values and one for new values. At the end of each iteration, the array of new values is copied to the array of old values to reset the data structures for the next iteration. This problem occurs in Fortran programs not included in this study and in both Fortran 77 and Fortran 90 code. Introducing pointers to the arrays and swapping pointer values is an obvious way to eliminate the copying; but pointers is not a feature that many Fortran programmers know well or are comfortable using. An easy solution not involving pointers is to extend the dimension of the value array by 1 and use the last dimension to differentiate between arrays at different times. For example, if the data space is N x N, declare the array (N, N, 2). Then store the problem’s initial values in (_, _, 2) and define the scalar names new = 2 and old = 1. At the start of each iteration, swap old and new to reset the arrays. The old–new copy problem did not appear in any C program. In programs that had new and old values, the code swapped pointers to reset data structures. Where unnecessary coping did occur is in structure assignment and parameter passing. Structures in C are handled much like scalars. Assignment causes the data space of the right-hand name to be copied to the data space of the left-hand name. Similarly, when a structure is passed to a function, the data space of the actual parameter is copied to the data space of the formal parameter. If the structure is large and the assignment or function call is in an inner loop, then copying costs can grow quite large. While none of the ten programs considered here manifested this problem, it did occur in programs not included in the study. A simple fix is always to refer to structures via pointers. Optimizing loop structures Since scientific programs spend almost all their time in loops, efficient loops are the key to good performance. Conditionals, function calls, little instruction level parallelism, and large numbers of temporary values make it difficult for the compiler to generate tightly packed, highly efficient code. Conditionals and function calls introduce jumps that disrupt code flow. Users should eliminate or isolate conditionls to their own loops as much as possible. Often logical expressions can be substituted for if-then-else statements. For example, code 2 includes the following snippet MaxDelta = 0.0 do J = 1, N do I = 1, M < code omitted > Delta = abs(OldValue ? NewValue) if (Delta > MaxDelta) MaxDelta = Delta enddo enddo if (MaxDelta .gt. 0.001) goto 200 Since the only use of MaxDelta is to control the jump to 200 and all that matters is whether or not it is greater than 0.001, I made MaxDelta a boolean and rewrote the snippet as MaxDelta = .false. do J = 1, N do I = 1, M < code omitted > Delta = abs(OldValue ? NewValue) MaxDelta = MaxDelta .or. (Delta .gt. 0.001) enddo enddo if (MaxDelta) goto 200 thereby, eliminating the conditional expression from the inner loop. A microprocessor can execute many instructions per instruction cycle. Typically, it can execute one or more memory, floating point, integer, and jump operations. To be executed simultaneously, the operations must be independent. Thick loops tend to have more instruction level parallelism than thin loops. Moreover, they reduce memory traffice by maximizing data reuse. Loop unrolling and loop fusion are two techniques to increase the size of loop bodies. Several of the codes studied benefitted from loop unrolling, but none benefitted from loop fusion. This observation is not too surpising since it is the general tendency of programmers to write thick loops. As loops become thicker, the number of temporary values grows, increasing register pressure. If registers spill, then memory traffic increases and code flow is disrupted. A thick loop with many temporary values may execute slower than an equivalent series of thin loops. The biggest gain will be achieved if the thick loop can be split into a series of independent loops eliminating the need to write and read temporary arrays. I found such an occasion in code 10 where I split the loop do i = 1, n do j = 1, m A24(j,i)= S24(j,i) * T24(j,i) + S25(j,i) * U25(j,i) B24(j,i)= S24(j,i) * T25(j,i) + S25(j,i) * U24(j,i) A25(j,i)= S24(j,i) * C24(j,i) + S25(j,i) * V24(j,i) B25(j,i)= S24(j,i) * U25(j,i) + S25(j,i) * V25(j,i) C24(j,i)= S26(j,i) * T26(j,i) + S27(j,i) * U26(j,i) D24(j,i)= S26(j,i) * T27(j,i) + S27(j,i) * V26(j,i) C25(j,i)= S27(j,i) * S28(j,i) + S26(j,i) * U28(j,i) D25(j,i)= S27(j,i) * T28(j,i) + S26(j,i) * V28(j,i) end do end do into two disjoint loops do i = 1, n do j = 1, m A24(j,i)= S24(j,i) * T24(j,i) + S25(j,i) * U25(j,i) B24(j,i)= S24(j,i) * T25(j,i) + S25(j,i) * U24(j,i) A25(j,i)= S24(j,i) * C24(j,i) + S25(j,i) * V24(j,i) B25(j,i)= S24(j,i) * U25(j,i) + S25(j,i) * V25(j,i) end do end do do i = 1, n do j = 1, m C24(j,i)= S26(j,i) * T26(j,i) + S27(j,i) * U26(j,i) D24(j,i)= S26(j,i) * T27(j,i) + S27(j,i) * V26(j,i) C25(j,i)= S27(j,i) * S28(j,i) + S26(j,i) * U28(j,i) D25(j,i)= S27(j,i) * T28(j,i) + S26(j,i) * V28(j,i) end do end do Conclusions Over the course of the last year, I have had the opportunity to work with over two dozen academic scientific programmers at leading research universities. Their research interests span a broad range of scientific fields. Except for two programs that relied almost exclusively on library routines (matrix multiply and fast Fourier transform), I was able to improve significantly the single processor performance of all codes. Improvements range from 2x to 15.5x with a simple average of 4.75x. Changes to the source code were at a very high level. I did not use sophisticated techniques or programming tools to discover inefficiencies or effect the changes. Only one code was parallel despite the availability of parallel systems to all developers. Clearly, we have a problem—personal scientific research codes are highly inefficient and not running parallel. The developers are unaware of simple optimization techniques to make programs run faster. They lack education in the art of code optimization and parallel programming. I do not believe we can fix the problem by publishing additional books or training manuals. To date, the developers in questions have not studied the books or manual available, and are unlikely to do so in the future. Short courses are a possible solution, but I believe they are too concentrated to be much use. The general concepts can be taught in a three or four day course, but that is not enough time for students to practice what they learn and acquire the experience to apply and extend the concepts to their codes. Practice is the key to becoming proficient at optimization. I recommend that graduate students be required to take a semester length course in optimization and parallel programming. We would never give someone access to state-of-the-art scientific equipment costing hundreds of thousands of dollars without first requiring them to demonstrate that they know how to use the equipment. Yet the criterion for time on state-of-the-art supercomputers is at most an interesting project. Requestors are never asked to demonstrate that they know how to use the system, or can use the system effectively. A semester course would teach them the required skills. Government agencies that fund academic scientific research pay for most of the computer systems supporting scientific research as well as the development of most personal scientific codes. These agencies should require graduate schools to offer a course in optimization and parallel programming as a requirement for funding. About the Author John Feo received his Ph.D. in Computer Science from The University of Texas at Austin in 1986. After graduate school, Dr. Feo worked at Lawrence Livermore National Laboratory where he was the Group Leader of the Computer Research Group and principal investigator of the Sisal Language Project. In 1997, Dr. Feo joined Tera Computer Company where he was project manager for the MTA, and oversaw the programming and evaluation of the MTA at the San Diego Supercomputer Center. In 2000, Dr. Feo joined Sun Microsystems as an HPC application specialist. He works with university research groups to optimize and parallelize scientific codes. Dr. Feo has published over two dozen research articles in the areas of parallel parallel programming, parallel programming languages, and application performance.

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