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  • Getting all objects with a certain element inside a collection of strings with criteria API.

    - by Jens Jansson
    Hey. I'm trying to build a Hibernate Criteria query to find entities that have a specific element inside a collection. We can take as an example a Book -object that looks like this: public class Book { private Long id; private String title; private Set<String> authors = new HashSet<String>(); } The entity is mapped like this: <class name="Book" table="Book"> <id name="id" column="BOOK_ID"> <generator class="native"/> </id> <property name="title"/> <set name="authors" table="Book_Authors"> <key column="BOOK_ID"/> <element type="string" column="AUTHORS"/> </set> </class> Now I would like to find out which books are written by Matt. With pure SQL I can do a query like this: String author = "Matt"; String query = "SELECT * FROM Book " + "WHERE BOOK_ID IN " + "(SELECT BOOK_ID FROM Book_Authors " + "WHERE authors = :author )"; List<Book> result = session.createSQLQuery(query) .addEntity(Book.class) .setParameter("author", author) .list(); This works all good and well, and I get out all books that Matt has been a part of writing. The project I work in, however, uses the Criteria API instead of raw SQL, and I haven't found a way to express the same query in that form. I've taken a look on the Restrictions API and the closest I've found is Restions.in(propertyName, collection) but that works the other way around (one value in object, many values to match against). Any ideas?

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  • How do I get a ComboBox SelectionChanged event to fire from a nested ListBoxItem?

    - by Stephen McCusker
    This is a rather complex problem that has me really confused right now. Any help would be greatly appreciated. The Setup: ListBox of Type A UserControls -ListBoxItem of Type A UserControl --ListBox of Type B UserControls ---ListBoxItem of Type B UserControl ----ListBox of Type C UserControls -----ListBoxItem of Type C UserControl (contains the ComboBox) In other words, the Type A control has a ListBox of Type B controls that has a ListBox of Type C controls. All of the controls are hierarchical in nature. Type A contains the data that's needed to load the Type B controls and the Type B contains the data that's needed to load the Type C controls. The Type C control has a standard ComboBox in it for changing the values of the present items. In addition to the above structure, I have drag and dropping tied to the PreviewMouseLeftButtonDown event on both the Type A and Type B UserControl levels to handle reordering/deleting/etc commands in the GUI. All of this is working as intended. The Problem: When I attempt to change the value in the ComboBox, the SelectionChanged event never fires on the Type C "level" unless I'm careful enough to click on the borders/spacing in between any Type A or B controls. This happens when my ComboBox popout menu overlaps on either a Type A or B control located below itself. The selection events for Type A or B are firing instead of the Type C events, so the ComboBox is never changing its value reliably. In the debugger, the code for handling the drag and drop is triggering on the next ListBoxItem that's located underneath the ComboBox. Thoughts: Is there a way I can make my ComboBox popup take prevalence over the items behind it while double-nested in a ListBox (ie, ignore anything behind it while it's open)? Is there some way to reroute the incorrectly firing SelectionChanged events down to the ComboBox that's supposed to be triggering them?

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  • How to perform Rails model validation checks within model but outside of filters using ledermann-rails-settings and extensions

    - by user1277160
    Background I'm using ledermann-rails-settings (https://github.com/ledermann/rails-settings) on a Rails 2/3 project to extend virtually the model with certain attributes that don't necessarily need to be placed into the DB in a wide table and it's working out swimmingly for our needs. An additional reason I chose this Gem is because of the post How to create a form for the rails-settings plugin which ties ledermann-rails-settings more closely to the model for the purpose of clean form_for usage for administrator GUI support. It's a perfect solution for addressing form_for support although... Something that I'm running into now though is properly validating the dynamic getters/setters before being passed to the ledermann-rails-settings module. At the moment they are saved immediately, regardless if the model validation has actually fired - I can see through script/console that validation errors are being raised. Example For instance I would like to validate that the attribute :foo is within the range of 0..100 for decimal usage (or even a regex). I've found that with the previous post that I can use standard Rails validators (surprise, surprise) but I want to halt on actually saving any values until those are addressed - ensure that the user of the GUI has given 61.43 as a numerical value. The following code has been borrowed from the quoted post. class User < ActiveRecord::Base has_settings validates_inclusion_of :foo, :in => 0..100 def self.settings_attr_accessor(*args) >>SOME SORT OF UNLESS MODEL.VALID? CHECK HERE args.each do |method_name| eval " def #{method_name} self.settings.send(:#{method_name}) end def #{method_name}=(value) self.settings.send(:#{method_name}=, value) end " end >>END UNLESS end settings_attr_accessor :foo end Anyone have any thoughts here on pulling the state of the model at this point outside of having to put this into a before filter? The goal here is to be able to use the standard validations and avoid rolling custom validation checks for each new settings_attr_accessor that is added. Thanks!

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  • How do you save and retrieve a Key/IV pair securely?

    - by Shawn Steward
    I'm using VB.Net's RijndaelManaged (RM) to encrypt files, using the RM.GenerateKey and RM.GenerateIV methods to generate the Key and IV and encrypting the file using the CryptoStream class. I'm planning on saving this Key and IV to a file and want to make sure I'm doing it the right way. I am combining the IV+Key, and encrypting that with my RSA Public key and writing it out to a file. Then, to decrypt I use the RSA Private key on this file to get the IV+Key, split them up and set RM.Key and RM.IV to these values and run the decryptor. Is this the best method to accomplish this, or is there a preferred method for saving the IV & Key? Also, what's the best way to construct and deconstruct the byte array? I used the .Concat method to join them together and that seems to work well but I can't seem to find something as easy to deconstruct it. I played with the .Take method that takes the first x # of bytes and it works for the first part but can't find anything that gets the rest of it.

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  • Trouble when changing pixel data with alpha on png on iphone --okay on simulator

    - by Ted
    I'm trying to change the color of the pixels (lighten or darken) without changing the value of the alpha channel using CGDataProviderCopyData. I leave every 4th databyte untouched. It work fine of the iphone simulator, however on the real thing the alpha goes white as I increase the values of the other pixels. I've tried changing just the first byte, or the second, or the third. Does anybody have any idea what is going on? The basic code is borrowed from Jorge. I like this simple approach --I'm new to this. But I want to make it work with png images with some transparency. here is most of the code by Jorge : CFDataRef CopyImagePixels(CGImageRef inImage){ return CGDataProviderCopyData(CGImageGetDataProvider(inImage)); } CGImageRef img=originalImage.CGImage; CFDataRef dataref=CopyImagePixels(img); UInt8 *data=(UInt8 *)CFDataGetBytePtr(dataref); int length=CFDataGetLength(dataref); for(int index=0;index255){ data[index+i]=255; }else{ data[index+i]+=value; } } } } size_t width=CGImageGetWidth(img); size_t height=CGImageGetHeight(img); size_t bitsPerComponent=CGImageGetBitsPerComponent(img); size_t bitsPerPixel=CGImageGetBitsPerPixel(img); size_t bytesPerRow=CGImageGetBytesPerRow(img); CGColorSpaceRef colorspace=CGImageGetColorSpace(img); CGBitmapInfo bitmapInfo=CGImageGetBitmapInfo(img); CGImageAlphaInfo alphaInfo = kCGBitmapAlphaInfoMask(img); NSLog(@"bitmapinfo: %d",bitmapInfo); CFDataRef newData=CFDataCreate(NULL,data,length); CGDataProviderRef provider=CGDataProviderCreateWithCFData(newData); CGImageRef newImg=CGImageCreate(width,height,bitsPerComponent,bitsPerPixel,bytesPerRow,colorspace,bitmapInfo,provider,NULL,true,kCGRenderingIntentDefault); [iv setImage:[UIImage imageWithCGImage:newImg]]; CGImageRelease(newImg); CGDataProviderRelease(provider);

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  • Switching languages on a website with PHP

    - by jnkrois
    Hello everybody, I'm just looking for some advice. I'm creating a website that offers (at least) 2 languages. The way I'm setting it up is by using XML files for the language, PHP to retrieve the values in the XML nodes. Say you have any XML file, being loaded as follows: <?php $lang = "en"; $xmlFile = simplexml_load_file("$lang/main.xml"); ?> Once the file contents are available, I just output each node into an HTML tag like so: <li><?php echo $xmlFile->navigation->home; ?></li> which in turn is equal to : <li><a href="#">Home</a></li> as a nav bar link. Now, the way in which I'm switching languages is by changing the value of the "$lang" variable, through a "$_POST", like so: if(isset($_POST['es'])){ $lang = "es"; }elseif(isset($_POST['en'])){ $lang = "en"; } The value of the "$lang" variable is reset and the new file is loaded, loading as well all the new nodes from the new XML file, hence changing the language. I'm just wondering if there is another way to reset the "$lang" variable using something else, other than "$_POST" or "$_GET". I don't want to use query string either. I know I could use JavaScript or jQuery to achieve this, but I'd like to make the site not too dependable on JavaScript. I'd appreciate any ideas or advice. Thanks

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  • How do I use a variable within an extended class public variable

    - by Gerry Humphrey
    Have a class that I am using, I am overriding variables in the class to change them to what values I need, but I also not sure if or how to handle an issue. I need to add a key that is generated to each of this URLs before the class calls them. I cannot modify the class file itself. use Theme/Ride class ETicket extends Ride { public $key='US20120303'; // Not in original class public $accessURL1 = 'http://domain.com/keycheck.php?key='.$key; public $accessURL2 = 'http://domain.com/keycheck.php?key='.$key; } I understand that you cannot use a variable in the setting of the public class variables. Just not sure what would be the way to actually do something like this in the proper format. My OOP skills are weak. I admit it. So if someone has a suggestion on where I could read up on it and get a clue, it would be appreciated as well. I guess I need OOP for Dummies. =/

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  • How to Implement Overlay blend method using opengles 1.1

    - by Cylon
    Blow is the algorithm of overlay. and i want using it on iphone, but iphone 3g only support opengles 1.1, can not using glsl. can i using blend function or texture combine to implement it. thank you /////////Reference from OpenGL Shading® Language Third Edition /////////// 19.6.12 Overlay OVERLAY first computes the luminance of the base value. If the luminance value is less than 0.5, the blend and base values are multiplied together. If the luminance value is greater than 0.5, a screen operation is performed. The effect is that the base value is mixed with the blend value, rather than being replaced. This allows patterns and colors to overlay the base image, but shadows and highlights in the base image are preserved. A discontinuity occurs where luminance = 0.5. To provide a smooth transition, we actually do a linear blend of the two equations for luminance in the range [0.45,0.55]. float luminance = dot(base, lumCoeff); if (luminance < 0.45) result = 2.0 * blend * base; else if (luminance 0.55) result = white - 2.0 * (white - blend) * (white - base); else { vec4 result1 = 2.0 * blend * base; vec4 result2 = white - 2.0 * (white - blend) * (white - base); result = mix(result1, result2, (luminance - 0.45) * 10.0); }

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  • PHP Preg_replace after a specific amount of characters with a conditional

    - by Marc Ripley
    I've been working on this for a bit, but my regex is weak. I need to check to see if a number is a whole number (single digit) and append a ".001" to it if so. The problem is, it's in the middle of a line with values separated by commas. MATERIALS,1,1,9999;1 4PL1 PB_Mel,,1,6,0.173,0.173,0.375,0,0.375,0,0,0,0,2,0,1,1 Needs to be MATERIALS,1,1,9999;1 4PL1 PB_Mel,,1.001,6,0.173,0.173,0.375,0,0.375,0,0,0,0,2,0,1,1 The line must start with "MATERIALS". There are more than one MATERIALS lines. The value will always be after 5 commas. I was trying something like this to even replace the number, but I don't think the approach is quite right: $stripped = preg_replace('/(MATERIALS)(,.*?){4}(,\d+?),/', '\2,', $stripped); I tried going through a preg_match_all for if process, to at least get the conditional working, but I still have to replace the lines. for($i=0;$i<sizeof($materialsLines[0]);$i++) { $section = explode(",",$materialsLines[0][$i]); if (strlen($section[5]) == 1) { $section[5] .= ".001"; } $materialsLines[0][$i] = implode(",",$section); }

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  • PHP error problem.

    - by TaG
    I get the following error on line 8: Undefined index: real_name which is $privacy_policy = mysqli_real_escape_string($mysqli, $_POST['privacy_policy']); I was wondering how can I fix this problem? Here is the PHP. if (isset($_POST['submitted'])) { $mysqli = mysqli_connect("localhost", "root", "", "sitename"); $dbc = mysqli_query($mysqli,"SELECT users.* FROM users WHERE user_id=3"); $privacy_policy = mysqli_real_escape_string($mysqli, $_POST['privacy_policy']); if (mysqli_num_rows($dbc) == 0) { $mysqli = mysqli_connect("localhost", "root", "", "sitename"); $dbc = mysqli_query($mysqli,"INSERT INTO users (user_id, privacy_policy) VALUES ('$user_id', '$privacy_policy')"); } if ($dbc == TRUE) { $dbc = mysqli_query($mysqli,"UPDATE users SET privacy_policy = '$privacy_policy' WHERE user_id = '$user_id'"); echo '<p class="changes-saved">Your changes have been saved!</p>'; } if (!$dbc) { print mysqli_error($mysqli); return; } } Here is the HTML. <form method="post" action="index.php"> <fieldset> <ul> <li><input type="checkbox" name="privacy_policy" id="privacy_policy" value="yes" <?php if (isset($_POST['privacy_policy'])) { echo 'checked="checked"'; } else if($privacy_policy == "yes") { echo 'checked="checked"'; } ?> /></li> <li><input type="submit" name="submit" value="Save Changes" class="save-button" /> <input type="hidden" name="submitted" value="true" /> <input type="submit" name="submit" value="Preview Changes" class="preview-changes-button" /></li> </ul> </fieldset> </form>

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  • Python unittest (using SQLAlchemy) does not write/update database?

    - by Jerry
    Hi, I am puzzled at why my Python unittest runs perfectly fine without actually updating the database. I can even see the SQL statements from SQLAlchemy and step through the newly created user object's email -- ...INFO sqlalchemy.engine.base.Engine.0x...954c INSERT INTO users (user_id, user_name, email, ...) VALUES (%(user_id)s, %(user_name)s, %(email)s, ...) ...INFO sqlalchemy.engine.base.Engine.0x...954c {'user_id': u'4cfdafe3f46544e1b4ad0c7fccdbe24a', 'email': u'[email protected]', ...} > .../tests/unit_tests/test_signup.py(127)test_signup_success() -> user = user_q.filter_by(user_name='test').first() (Pdb) n ...INFO sqlalchemy.engine.base.Engine.0x...954c SELECT users.user_id AS users_user_id, ... FROM users WHERE users.user_name = %(user_name_1)s LIMIT 1 OFFSET 0 ...INFO sqlalchemy.engine.base.Engine.0x...954c {'user_name_1': 'test'} > .../tests/unit_tests/test_signup.py(128)test_signup_success() -> self.assertTrue(isinstance(user, model.User)) (Pdb) user <pweb.models.User object at 0x9c95b0c> (Pdb) user.email u'[email protected]' Yet at the same time when I login to the test database, I do not see the new record there. Is it some feature from Python/unittest/SQLAlchemy/Pyramid/PostgreSQL that I'm totally unaware of? Thanks. Jerry

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  • Improving the performance of XSL

    - by Rachel
    I am using the below XSL 2.0 code to find the ids of the text nodes that contains the list of indices that i give as input. the code works perfectly but in terms for performance it is taking a long time for huge files. Even for huge files if the index values are small then the result is quick in few ms. I am using saxon9he Java processor to execute the XSL. <xsl:variable name="insert-data" as="element(data)*"> <xsl:for-each-group select="doc($insert-file)/insert-data/data" group-by="xsd:integer(@index)"> <xsl:sort select="current-grouping-key()"/> <data index="{current-grouping-key()}" text-id="{generate-id( $main-root/descendant::text()[ sum((preceding::text(), .)/string-length(.)) ge current-grouping-key() ][1] )}"> <xsl:copy-of select="current-group()/node()"/> </data> </xsl:for-each-group> </xsl:variable> In the above solution if the index value is too huge say 270962 then the time taken for the XSL to execute is 83427ms. In huge files if the index value is huge say 4605415, 4605431 it takes several minutes to execute. Seems the computation of the variable "insert-data" takes time though it is a global variable and computed only once. Should the XSL be addessed or the processor? How can i improve the performance of the XSL.

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  • Validating Login / Changing User settings / Php Mysql

    - by Marcelo
    Hi everyone, my questions are about login, and changing already saved data. (Q1) 'Till now I've only saved input in the tables of the database (registration steps), now I need to check if the input (login steps), are the same of my table in database, in fact I have 3 types of users, then I'll have to check 3 kind of tables. Then if the input data matches with one of those 3 tables I will redirect the user to his specific area. I'm thinking about saved the submitted data $login=$_REQUEST['login']; and $password=$_REQUEST['password']; and compare with the login column in the database. Then if the login matches, I'll compare the password submitted with the one in the row, not in the column. But I don't know how to do this search and comparison,neither what to use. Then if both matches I'll redirect the user. Else I'll send an login error message. (this I know how to do) (Q2) What if need to change an already saved user ? For example to change an email address. My changing user's data web page is exactly the same like the registration user web page. Can I load the already saved options and values of registration (table user for example). Then the user will change whatever he thinks it's necessary, and then when he submits the new information, they would not create a new row in my table, but just be overwritten the old information? How can I do this? Sorry for any mistake in English, and Thanks for the attention.

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  • mvc post techniques

    - by user281180
    My form is as follows, how can I retrieve the values in my controller: <% using (Html.BeginForm("Create","Employee")) {% <%= Html.ValidationSummary()% <p><label for = "Name" >Name</label> <%= Html.TextBoxFor(model => model.EmployeeName)%> <%= Html.ValidationMessageFor(model => model.EmployeeName)%> </p> <label for = "ProName">Project</label> <table id="projectTable"> <tr> <td> <label for="Name" id = 1>UT1</label></td></tr> <tr> <td> <label for="Name" id= 2>UT2</label></td></tr> </table> <input type ="submit" value="Save" id="submit" /> <% }%>

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  • uploading image & getting back from database

    - by Anup Prakash
    Putting a set of code which is pushing image to database and fetching back from database: <!-- <?php error_reporting(0); // Connect to database $errmsg = ""; if (! @mysql_connect("localhost","root","")) { $errmsg = "Cannot connect to database"; } @mysql_select_db("test"); $q = <<<CREATE create table image ( pid int primary key not null auto_increment, title text, imgdata longblob, friend text) CREATE; @mysql_query($q); // Insert any new image into database if (isset($_POST['submit'])) { move_uploaded_file($_FILES['imagefile']['tmp_name'],"latest.img"); $instr = fopen("latest.img","rb"); $image = addslashes(fread($instr,filesize("latest.img"))); if (strlen($instr) < 149000) { $image_query="insert into image (title, imgdata,friend) values (\"". $_REQUEST['title']. "\", \"". $image. "\",'".$_REQUEST['friend']."')"; mysql_query ($image_query) or die("query error"); } else { $errmsg = "Too large!"; } $resultbytes=''; // Find out about latest image $query = "select * from image where pid=1"; $result = @mysql_query("$query"); $resultrow = @mysql_fetch_assoc($result); $gotten = @mysql_query("select * from image order by pid desc limit 1"); if ($row = @mysql_fetch_assoc($gotten)) { $title = htmlspecialchars($row[title]); $bytes = $row[imgdata]; $resultbytes = $row[imgdata]; $friend=$row[friend]; } else { $errmsg = "There is no image in the database yet"; $title = "no database image available"; // Put up a picture of our training centre $instr = fopen("../wellimg/ctco.jpg","rb"); $bytes = fread($instr,filesize("../wellimg/ctco.jpg")); } if ($resultbytes!='') { echo $resultbytes; } } ?> <html> <head> <title>Upload an image to a database</title> </head> <body bgcolor="#FFFF66"> <form enctype="multipart/form-data" name="file_upload" method="post"> <center> <div id="image" align="center"> <h2>Heres the latest picture</h2> <font color=red><?php echo $errmsg; ?></font> <b><?php echo $title ?></center> </div> <hr> <h2>Please upload a new picture and title</h2> <table align="center"> <tr> <td>Select image to upload: </td> <td><input type="file" name="imagefile"></td> </tr> <tr> <td>Enter the title for picture: </td> <td><input type="text" name="title"></td> </tr> <tr> <td>Enter your friend's name:</td> <td><input type="text" name="friend"></td> </tr> <tr> <td><input type="submit" name="submit" value="submit"></td> <td></td> </tr> </table> </form> </body> </html> --> Above set of code has one problem. The problem is whenever i pressing the "submit" button. It is just displaying the image on a page. But it is leaving all the html codes. even any new line message after the // Printing image on browser echo $resultbytes; //************************// So, for this i put this set of code in html tag: This is other sample code: <!-- <?php error_reporting(0); // Connect to database $errmsg = ""; if (! @mysql_connect("localhost","root","")) { $errmsg = "Cannot connect to database"; } @mysql_select_db("test"); $q = <<<CREATE create table image ( pid int primary key not null auto_increment, title text, imgdata longblob, friend text) CREATE; @mysql_query($q); // Insert any new image into database if (isset($_POST['submit'])) { move_uploaded_file($_FILES['imagefile']['tmp_name'],"latest.img"); $instr = fopen("latest.img","rb"); $image = addslashes(fread($instr,filesize("latest.img"))); if (strlen($instr) < 149000) { $image_query="insert into image (title, imgdata,friend) values (\"". $_REQUEST['title']. "\", \"". $image. "\",'".$_REQUEST['friend']."')"; mysql_query ($image_query) or die("query error"); } else { $errmsg = "Too large!"; } $resultbytes=''; // Find out about latest image $query = "select * from image where pid=1"; $result = @mysql_query("$query"); $resultrow = @mysql_fetch_assoc($result); $gotten = @mysql_query("select * from image order by pid desc limit 1"); if ($row = @mysql_fetch_assoc($gotten)) { $title = htmlspecialchars($row[title]); $bytes = $row[imgdata]; $resultbytes = $row[imgdata]; $friend=$row[friend]; } else { $errmsg = "There is no image in the database yet"; $title = "no database image available"; // Put up a picture of our training centre $instr = fopen("../wellimg/ctco.jpg","rb"); $bytes = fread($instr,filesize("../wellimg/ctco.jpg")); } } ?> <html> <head> <title>Upload an image to a database</title> </head> <body bgcolor="#FFFF66"> <form enctype="multipart/form-data" name="file_upload" method="post"> <center> <div id="image" align="center"> <h2>Heres the latest picture</h2> <?php if ($resultbytes!='') { // Printing image on browser echo $resultbytes; } ?> <font color=red><?php echo $errmsg; ?></font> <b><?php echo $title ?></center> </div> <hr> <h2>Please upload a new picture and title</h2> <table align="center"> <tr> <td>Select image to upload: </td> <td><input type="file" name="imagefile"></td> </tr> <tr> <td>Enter the title for picture: </td> <td><input type="text" name="title"></td> </tr> <tr> <td>Enter your friend's name:</td> <td><input type="text" name="friend"></td> </tr> <tr> <td><input type="submit" name="submit" value="submit"></td> <td></td> </tr> </table> </form> </body> </html> --> ** But in this It is showing the image in format of special charaters and digits. 1) So, Please help me to print the image with some HTML code. So that i can print it in my form to display the image. 2) Is there any way to convert the database image into real image, so that i can store it into my hard-disk and call it from tag? Please help me.

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  • Collapsing data frame by selecing one row per group

    - by jkebinger
    I'm trying to collapse a data frame by removing all but one row from each group of rows with identical values in a particular column. In other words, the first row from each group. For example, I'd like to convert this > d = data.frame(x=c(1,1,2,4),y=c(10,11,12,13),z=c(20,19,18,17)) > d x y z 1 1 10 20 2 1 11 19 3 2 12 18 4 4 13 17 Into this: x y z 1 1 11 19 2 2 12 18 3 4 13 17 I'm using aggregate to do this currently, but the performance is unacceptable with more data: > d.ordered = d[order(-d$y),] > aggregate(d.ordered,by=list(key=d.ordered$x),FUN=function(x){x[1]}) I've tried split/unsplit with the same function argument as here, but unsplit complains about duplicate row numbers. Is rle a possibility? Is there an R idiom to convert rle's length vector into the indices of the rows that start each run, which I can then use to pluck those rows out of the data frame?

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  • C: 8x8 -> 16 bit multiply precision guaranteed by integer promotions?

    - by craig-blome
    I'm trying to figure out if the C Standard (C90, though I'm working off Derek Jones' annotated C99 book) guarantees that I will not lose precision multiplying two unsigned 8-bit values and storing to a 16-bit result. An example statement is as follows: unsigned char foo; unsigned int foo_u16 = foo * 10; Our Keil 8051 compiler (v7.50 at present) will generate a MUL AB instruction which stores the MSB in the B register and the LSB in the accumulator. If I cast foo to a unsigned int first: unsigned int foo_u16 = (unsigned int)foo * 10; then the compiler correctly decides I want a unsigned int there and generates an expensive call to a 16x16 bit integer multiply routine. I would like to argue beyond reasonable doubt that this defensive measure is not necessary. As I read the integer promotions described in 6.3.1.1, the effect of the first line shall be as if foo and 10 were promoted to unsigned int, the multiplication performed, and the result stored as unsigned int in foo_u16. If the compiler knows an instruction that does 8x8-16 bit multiplications without loss of precision, so much the better; but the precision is guaranteed. Am I reading this correctly? Best regards, Craig Blome

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  • Deeply nested subqueries for traversing trees in MySQL

    - by nickf
    I have a table in my database where I store a tree structure using the hybrid Nested Set (MPTT) model (the one which has lft and rght values) and the Adjacency List model (storing parent_id on each node). my_table (id, parent_id, lft, rght, alias) This question doesn't relate to any of the MPTT aspects of the tree but I thought I'd leave it in in case anyone had a good idea about how to leverage that. I want to convert a path of aliases to a specific node. For example: "users.admins.nickf" would find the node with alias "nickf" which is a child of one with alias "admins" which is a child of "users" which is at the root. There is a unique index on (parent_id, alias). I started out by writing the function so it would split the path to its parts, then query the database one by one: SELECT `id` FROM `my_table` WHERE `parent_id` IS NULL AND `alias` = 'users';-- 1 SELECT `id` FROM `my_table` WHERE `parent_id` = 1 AND `alias` = 'admins'; -- 8 SELECT `id` FROM `my_table` WHERE `parent_id` = 8 AND `alias` = 'nickf'; -- 37 But then I realised I could do it with a single query, using a variable amount of nesting: SELECT `id` FROM `my_table` WHERE `parent_id` = ( SELECT `id` FROM `my_table` WHERE `parent_id` = ( SELECT `id` FROM `my_table` WHERE `parent_id` IS NULL AND `alias` = 'users' ) AND `alias` = 'admins' ) AND `alias` = 'nickf'; Since the number of sub-queries is dependent on the number of steps in the path, am I going to run into issues with having too many subqueries? (If there even is such a thing) Are there any better/smarter ways to perform this query?

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  • spring.net proxy factory with target type needs property virtual ?

    - by Vince
    Hi all, I'm creating spring.net proxy in code by using ProxyFactory object with ProxyTargetType to true to have a proxy on a non interfaced complex object. Proxying seems ok till i call a method on that object. The method references a public property and if this property is not virtual it's value is null. This doesn't happen if i use Spring.Aop.Framework.AutoProxy.InheritanceBasedAopConfigurer in spring config file but in this case i can't use this because spring context doesn't own this object. Is this normal to have such behavior or is there a tweak to perform what i want (proxying object virtual method without having to change properties virtual)? Note that i tried factory.AutoDetectInterfaces and factory.ProxyTargetAttributes values but doesn't help. My proxy creation code: public static T CreateMethodCallStatProxy<T>() { // Proxy factory ProxyFactory factory = new ProxyFactory(); factory.AddAdvice(new CallMonitorTrackerAdvice()); factory.ProxyTargetType = true; // Create instance factory.Target = Activator.CreateInstance<T>(); // Get proxy T proxiedClass = (T)factory.GetProxy(); return proxiedClass; } Thanks for your help

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  • PHP: Next Available Value in an Array, starting with a non-indexed value

    - by Erik Smith
    I've been stumped on this PHP issue for about a day now. Basically, we have an array of hours formatted in 24-hour format, and an arbitrary value ($hour) (also a 24-hour). The problem is, we need to take $hour, and get the next available value in the array, starting with the value that immediately proceeds $hour. The array might look something like: $goodHours = array('8,9,10,11,12,19,20,21). Then the hour value might be: $hour = 14; So, we need some way to know that 19 is the next best time. Additionally, we might also need to get the second, third, or fourth (etc) available value. The issue seems to be that because 14 isn't a value in the array, there is not index to reference that would let us increment to the next value. To make things simpler, I've taken $goodHours and repeated the values several times just so I don't have to deal with going back to the start (maybe not the best way to do it, but a quick fix). I have a feeling this is something simple I'm missing, but I would be so appreciative if anyone could shed some light. Erik

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  • Communication between parent and child

    - by Pierre
    Hi every one ! I have a little problem. I have to code a simple C application that creat a process and his child (fork()) and I have to do an operation. Parent initialize the values and child calculate. I write this : #include #include #include #include #include typedef struct { int op1; char op; int op2; }Operation; Operation *varOP; void finalResult() { float result = 0; if(varOP-op == '+') result = (varOP-op1 + varOP-op2); if(varOP-op == '-') result = (varOP-op1 - varOP-op2); if(varOP-op == '*') result = (varOP-op1 * varOP-op2); if(varOP-op == '+') result = (varOP-op1 / varOP-op2); printf("%f",result); } int main () { int p; varOP = (Operation *)malloc(sizeof(Operation)); p = fork(); if(p == 0) // If child { signal(SIGUSR1, finalResult ); pause(); } if(p 0) // If parent { varOP-op = '+'; varOP-op1 = 2; varOP-op2 = 3; kill(p, SIGUSR1); wait(NULL); } return 0; } But my child is never called. Is there something wrong with my code? Thanks for your help !

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  • Rails - eager load the number of associated records, but not the record themselves.

    - by Max Williams
    I have a page that's taking ages to render out. Half of the time (3 seconds) is spent on a .find call which has a bunch of eager-loaded associations. All i actually need is the number of associated records in each case, to display in a table: i don't need the actual records themselves. Is there a way to just eager load the count? Here's a simplified example: @subjects = Subject.find(:all, :include => [:questions]) In my table, for each row (ie each subject) i just show the values of the subject fields and the number of associated questions for each subject. Can i optimise the above find call to suit these requirements? I thought about using a group field but my full call has a few different associations included, with some second-order associations, so i don't think group by will work. @subjects = Subject.find(:all, :include => [{:questions => :tags}, {:quizzes => :tags}], :order => "subjects.name") :tags in this case is a second-order association, via taggings. Here's my associations in case it's not clear what's going on. Subject has_many :questions has_many :quizzes Question belongs_to :subject has_many :taggings has_many :tags, :through => :taggings Quiz belongs_to :subject has_many :taggings has_many :tags, :through => :taggings Grateful for any advice - max

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  • How Do I Escape Apostrophes in Field Valued in SQL Server?

    - by Mikecancook
    I asked a question a couple days ago about creating INSERTs by running a SELECT to move data to another server. That worked great until I ran into a table that has full on HTML and apostrophes in it. What's the best way to deal with this? Lucking there aren't too many rows so it is feasible as a last resort to 'copy and paste'. But, eventually I will need to do this and the table by that time will probably be way too big to copy and paste these HTML fields. This is what I have now: select 'Insert into userwidget ([Type],[UserName],[Title],[Description],[Data],[HtmlOutput],[DisplayOrder],[RealTime],[SubDisplayOrder]) VALUES (' + ISNULL('N'''+Convert(varchar(8000),Type)+'''','NULL') + ',' + ISNULL('N'''+Convert(varchar(8000),Username)+'''','NULL') + ',' + ISNULL('N'''+Convert(varchar(8000),Title)+'''','NULL') + ',' + ISNULL('N'''+Convert(varchar(8000),Description)+'''','NULL') + ',' + ISNULL('N'''+Convert(varchar(8000),Data)+'''','NULL') + ',' + ISNULL('N'''+Convert(varchar(8000),HTMLOutput)+'''','NULL') + ',' + ISNULL('N'''+Convert(varchar(8000),DisplayOrder)+'''','NULL') + ',' + ISNULL('N'''+Convert(varchar(8000),RealTime)+'''','NULL') + ',' + ISNULL('N'''+Convert(varchar(8000),SubDisplayOrder)+'''','NULL') + ')' from userwidget Which is works fine except those pesky apostrophes in the HTMLOutput field. Can I escape them by having the query double up on the apostrophes or is there a way of encoding the field result so it won't matter?

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  • How do I bring forward the SELECTED option in PHP from MySQL?

    - by Derek
    Hi all, In my update form, I want the fields to recall the values that are already stored. This is very simple in a text field, but for my drop down () I'm having trouble with PHP reading the already stored name of user. Here is my query and code: $sql = "SELECT users.user_id, users.name FROM users"; $result = mysql_query($sql, $connection) or die ("Couldn't perform query $sql <br />".mysql_error()); $row = mysql_fetch_array($result);?> <label>Designated Person:</label> <select name="name" id="name"> <option value="<?php echo $row['user_id']?>" SELECTED><?php echo $row['name']?> - Current</option> <?php while($row = mysql_fetch_array($result)) { ?> <option value="<?php echo $row['user_id']; if (isset($_POST['user_id']));?>"><?php echo $row['fullname']?></option> <?php } ?> The result of this displays all of the users (as required) and lets me select a user then perform the change successfully...however the 'SELECTED' is always the first one in my database and never the user that was selected when my activity was added :( !!!

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  • Dependency Property ListBox

    - by developer
    Hi All, I want to use a dependency property, so that my label displays values selected in the listbox. This is just to more clearly understand the working of a dependency property. <Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:WPFToolkit="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit" xmlns:local="clr-namespace:WpfApplication1" x:Name="MyWindow" Height="200" Width="300" > <StackPanel> <ListBox x:Name="lbColor" Width="248" Height="56" ItemsSource="{Binding TestColor}"/> <StackPanel> <Label Content="{Binding Path=Test, ElementName=lbColor}" /> </StackPanel> </StackPanel> </Window> Code Behind, namespace WpfApplication1 { /// <summary> /// Interaction logic for Window1.xaml /// </summary> public partial class Window1 : Window { public ObservableCollection<string> TestColor { get; set; } public String Test { get { return (String)GetValue(TestProperty); } set { SetValue(TestProperty, value); } } // Using a DependencyProperty as the backing store for Title. This enables animation, styling, binding, etc... public static readonly DependencyProperty TestProperty = DependencyProperty.Register("Test", typeof(String), typeof(ListBox), new UIPropertyMetadata("Test1")); public Window1() { InitializeComponent(); TestColor = new ObservableCollection<string>(); DataContext = this; TestColor.Add("Red"); TestColor.Add("Orange"); TestColor.Add("Yellow"); TestColor.Add("Green"); TestColor.Add("Blue"); } } } Can anyone explain me how will I accompalish this using a dependency property. Somehow I am very confused with the Dependency Property concept, and I just wanted to see a working example for that.

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