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  • multi-dimension array value sorting in php

    - by David
    Another potentially interesting (or n00b, whatever comes first) question. I am building up an array with a set of database fields with information about table, actual field name and descriptive field name as a multi-dimensional array. Here is what it currently looks like: $Fields['User']['ID'] = "User ID"; $Fields['User']['FirstName'] = "First Name"; $Fields['Stats']['FavouriteOrder'] = "Favourite Item Ordered"; $Fields['Geographic']['Location'] = "Current Location"; $Fields['Geographic']['LocationCode'] = "Current Location Code"; Okay, this is fine, but I am piping this into a system that allows exporting of selected fields, and in the end I want to foreach() through the different levels, extract the data and then ultimately have all the descriptive fields to be displayed sorted alphabetically using their descriptive name. So ultimately in the order: Current Location, Current Location Code, Favourite Item Ordered, First Name then User ID - obviously keeping index associations. I can't use usort() and I can't use array_multisort()... or maybe I can and I just don't know how. usort() seems to need a key to sort by, but I have variable keys. array_multisort() just seems to do the same as sort() really. Any ideas?

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  • Implementation of "Automatic Lightweight Migration" for Core Data (iPhone)

    - by RickiG
    Hi I would like to make my app able to do an automatic lightweight migration when I add new attributes to my core data model. In the guide from Apple this is the only info on the subject I could find: Automatic Lightweight Migration To request automatic lightweight migration, you set appropriate flags in the options dictionary you pass in addPersistentStoreWithType:configuration:URL:options:error:. You need to set values corresponding to both the NSMigratePersistentStoresAutomaticallyOption and the NSInferMappingModelAutomaticallyOption keys to YES: NSError *error; NSURL *storeURL = <#The URL of a persistent store#>; NSPersistentStoreCoordinator *psc = <#The coordinator#>; NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil]; if (![psc addPersistentStoreWithType:<#Store type#> configuration:<#Configuration or nil#> URL:storeURL options:options error:&error]) { // Handle the error. } My NSPersistentStoreCoordinator is initialized in this way: - (NSPersistentStoreCoordinator *)persistentStoreCoordinator { if (persistentStoreCoordinator != nil) { return persistentStoreCoordinator; } NSURL *storeUrl = [NSURL fileURLWithPath: [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"FC.sqlite"]]; NSError *error = nil; persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]]; if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:&error]) { NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } return persistentStoreCoordinator; } I am having trouble seeing where and how I should add the Apple code to get the Automatic Lightweight Migration working?

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  • Ideas for jumping in 2D with Actionscript 3 [included attempt]

    - by befall
    So, I'm working on the basics of Actionscript 3; making games and such. I designed a little space where everything is based on location of boundaries, using pixel-by-pixel movement, etc. So far, my guy can push a box around, and stops when running into the border, or when try to the push the box when it's against the border. So, next, I wanted to make it so when I bumped into the other box, it shot forward; a small jump sideways. I attempted to use this (foolishly) at first: // When right and left borders collide. if( (box1.x + box1.width/2) == (box2.x - box2.width/2) ) { // Nine times through for (var a:int = 1; a < 10; a++) { // Adds 1, 2, 3, 4, 5, 4, 3, 2, 1. if (a <= 5) { box2.x += a; } else { box2.x += a - (a - 5)*2 } } } Though, using this in the function I had for the movement (constantly checking for keys up, etc) does this all at once. Where should I start going about a frame-by-frame movement like that? Further more, it's not actually frames in the scene, just in the movement. This is a massive pile of garbage, I apologize, but any help would be appreciated.

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  • User preferences using SQL and JavaScript

    - by Shyam
    Hi, I am using Server Side JavaScript - yes, I am actually using Server Side JavaScript. To complexify things even more, I use Oracle as a backend database (10g). With some crazy XSLT and mutant-like HTML generation, I can build really fancy web forms - yes, I am aware of Rails and other likewise frameworks and I choose the path of horror instead. I have no JQuery or other fancy framework at my disposal, just plain ol' JavaScript that should be supported by the underlying engine called Mozilla Rhino. Yes, it is insane and I love it. So, I have a bunch of tables at my disposal and some of them are filled with associative keys that link to values. As I am a people pleaser, I want to add some nifty user-preference driven solutions. My users have all an unique user_id and this user_id is available during the entire session. My initial idea is to have a user preference table, where I have "three" columns: user_id, feature and pref_string. Using a delimiter, such as : or - (haven't thought about a suitable one yet), I could like store a bunch of preferences as a list and store its elements inside an array using the .split-method (similar like the PHP-explode function). The feature column could be like the table name or some identifier for the "feature" i want to link preferences too. I hate hardcoding objects, especially as I want to be able to back these up and reuse this functionality application-wide. Of course I would love better ideas, just keep in mind I cannot just add a library that easily. These preferences could be like "joined" to the table, so I can query it and use its values. I hope it doesn't sounds too complex, because well.. its basically something really simple I need. Thanks!

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  • Why does Hibernate ignore the JPA2 standardized properties in my persistence.xml?

    - by Ophidian
    I have an extremely simple web application running in Tomcat using Spring 3.0.1, Hibernate 3.5.1, JPA 2, and Derby. I am defining all of my database connectivity in persistence.xml and merely using Spring for dependency injection. I am using embedded Derby as my database. Everything works correctly when I define the driver and url properties in persistence.xml in the classic Hibernate manner as thus: <property name="hibernate.connection.driver_class" value="org.apache.derby.jdbc.EmbeddedDriver"/> <property name="hibernate.connection.url" value="jdbc:derby:webdb;create=true"/> The problems occur when I switch my configuration to the JPA2 standardized properties as thus: <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver"/> <property name="javax.persistence.jdbc.url" value="jdbc:derby:webdb;create=true"/> When using the JPA2 property keys, the application bails hard with the following exception: java.lang.UnsupportedOperationException: The user must supply a JDBC connection Does anyone know why this is failing? NOTE: I have copied the javax... property strings straight from the Hibernate reference documentation, so a typo is extremely unlikely.

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  • Counting total sum of each value in one column w.r.t another in Perl

    - by sfactor
    I have tab delimited data with multiple columns. I have OS names in column 31 and data bytes in columns 6 and 7. What I want to do is count the total volume of each unique OS. So, I did something in Perl like this: #!/usr/bin/perl use warnings; my @hhfilelist = glob "*.txt"; my %count = (); for my $f (@hhfilelist) { open F, $f || die "Cannot open $f: $!"; while (<F>) { chomp; my @line = split /\t/; # counting volumes in col 6 and 7 for 31 $count{$line[30]} = $line[5] + $line[6]; } close (F); } my $w = 0; foreach $w (sort keys %count) { print "$w\t$count{$w}\n"; } So, the result would be something like Windows 100000 Linux 5000 Mac OSX 15000 Android 2000 But there seems to be some error in this code because the resulting values I get aren't as expected. What am I doing wrong?

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  • How to check if JavaScript object is JSON

    - by Wei Hao
    I have a nested JSON object that I need to loop through, and the value of each key could be a String, JSON array or another JSON object. Depending on the type of object, I need to carry out different operations. Is there any way I can check the type of the object to see if it is a String, JSON object or JSON array? I tried using typeof and instanceof but both didn't seem to work, as typeof will return an object for both JSON object and array, and instanceof gives an error when I do obj instanceof JSON. To be more specific, after parsing the JSON into a JS object, is there any way I can check if it is a normal string, or an object with keys and values (from a JSON object), or an array (from a JSON array)? For example: JSON var data = {"hi": {"hello": ["hi1","hi2"] }, "hey":"words" } JavaScript var jsonObj = JSON.parse(data); var level1 = jsonObj.hi; var text = jsonObj.hey; var arr = level1.hello; //how to check if level1 was formerly a JSON object? //how to check if arr was formerly a JSON array? //how to check if text is a string?

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  • I can't figure out why this fps counter is inaccurate.

    - by rmetzger
    I'm trying to track frames per second in my game. I don't want the fps to show as an average. I want to see how the frame rate is affected when I push keys and add models etc. So I am using a variable to store the current time and previous time, and when they differ by 1 second, then I update the fps. My problem is that it is showing around 33fps but when I move the mouse around really fast, the fps jumps up to 49fps. Other times, if I change a simple line of code elsewhere not related to the frame counter, or close the project and open it later, the fps will be around 60. Vsync is on so I can't tell if the mouse is still effecting the fps. Here is my code which is in an update function that happens every frame: FrameCount++; currentTime = timeGetTime (); static unsigned long prevTime = currentTime; TimeDelta = (currentTime - prevTime) / 1000; if (TimeDelta > 1.0f) { fps = FrameCount / TimeDelta; prevTime = currentTime; FrameCount = 0; TimeDelta = 0; } Here are the variable declarations: int FrameCount; double fps, currentTime, prevTime, TimeDelta, TimeElapsed; Please let me know what is wrong here and how to fix it, or if you have a better way to count fps. Thanks!!!!!! I am using DirectX 9 btw but I doubt that is relevant, and I am using PeekMessage. Should I be using an if else statement instead? Here is my message processing loop: MSG msg; ZeroMemory (&msg, sizeof (MSG)); while (msg.message != WM_QUIT) { if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { TranslateMessage (&msg); DispatchMessage (&msg); } Update (); RenderFrame (); }

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  • Is it possible to group records belonging to an entity in dbunit?

    - by Joshua
    Our JPA entity model auto-generates primary key identifiers for user, user_address tables. Would it be possible to group these entities given below via dbunit, so that I don't need to provide neither the primary key as well as the foreign key reference from user_address.user_id. It is getting very hard to maintain these keys (i.e. I would prefer to group the primary record 'user' and the child records 'user_address' so that dbunit can group them automatically by looking up the entity metadata). Is it achievable? <user id="1" first_name="Josh" creation_date="2009-07-11 15:45:28"/> <user_address id="1" user_id="1" address="Main St" city="Los Angeles"/> I would prefer something like this <!-- First user --> <user first_name="Josh" creation_date="2009-07-11 15:45:28"/> <user_address address="Main St" city="Los Angeles"/> <!-- Second user --> <user first_name="Mary" creation_date="2009-07-11 15:45:28"/> <user_address address="Taylors St" city="San Jose"/>

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  • How to create an AST with ANTLR from a hierarchical key-value syntax

    - by Brabster
    I've been looking at parsing a key-value data format with ANTLR. Pretty straightforward, but the keys represent a hierarchy. A simplified example of my input syntax: /a/b/c=2 /a/b/d/e=3 /a/b/d/f=4 In my mind, this represents a tree structured as follows: (a (b (= c 2) (d (= e 3) (= f 4)))) The nearest I can get is to use the following grammar: /* Parser Rules */ start: (component NEWLINE?)* EOF -> (component)*; component: FORWARD_SLASH ALPHA_STRING component -> ^(ALPHA_STRING component) | FORWARD_SLASH ALPHA_STRING EQUALS value -> ^(EQUALS ALPHA_STRING value); value: ALPHA_STRING; /* Lexer Rules */ NEWLINE : '\r'? '\n'; ALPHA_STRING : ('a'..'z'|'A'..'Z'|'0'..'9')+; EQUALS : '='; FORWARD_SLASH : '/'; Which produces: (a (b (= c 2))) (a (b (d (= e 3)))) (a (b (d (= f 4)))) I'm not sure whether I'm asking too much from a generic tool such as ANTLR here, and this is as close I can get with this approach. That is, from here I consume the parts of the tree and create the data structure I want by hand. So - can I produce the tree structure I want directly from a grammar? If so, how? If not, why not - is it a technical limitation in ANTLR or is it something more CS-y to do with the type of language involved?

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  • Routing problem with calling a new method without an ID

    - by alkaloids
    I'm trying to put together a form_tag that edits several Shift objects. I have the form built properly, and it's passing on the correct parameters. I have verified that the parameters work with updating the objects correctly in the console. However, when I click the submit button, I get the error: ActiveRecord::RecordNotFound in ShiftsController#update_individual Couldn't find Shift without an ID My route for the controller it is calling looks like this looks like this: map.resources :shifts, :collection => { :update_individual => :put } The method in ShiftsController is this: def update_individual Shift.update(params[:shifts].keys, params[:shifts].values) flash[:notice] = "Schedule saved" end The relevant form parts are these: <% form_tag( update_individual_shifts_path ) do %> ... (fields for...) <%= submit_tag "Save" %> <% end %> Why is this not working? If I browse to the url: "http://localhost:3000/shifts/update_individual/5" (or any number that corresponds to an existing shift), I get the proper error about having no parameters set, but when I pass parameters without an ID of some sort, it errors out. How do I make it stop looking for an ID at the end of the URL?

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  • My cocoa app won't capture key events

    - by Oscar
    Hi, i usually develop for iPhone. But now trying to make a pong game in Cocoa desktop application. Working out pretty well, but i can't find a way to capture key events. Here's my code: #import "PongAppDelegate.h" #define GameStateRunning 1 #define GameStatePause 2 #define BallSpeedX 10 #define BallSpeedY 15 @implementation PongAppDelegate @synthesize window, leftPaddle, rightPaddle, ball; - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { gameState = GameStateRunning; ballVelocity = CGPointMake(BallSpeedX, BallSpeedY); [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(gameLoop) userInfo:nil repeats:YES]; } - (void)gameLoop { if(gameState == GameStateRunning) { [ball setFrameOrigin:CGPointMake(ball.frame.origin.x + ballVelocity.x, ball.frame.origin.y + ballVelocity.y)]; if(ball.frame.origin.x + 15 > window.frame.size.width || ball.frame.origin.x < 0) { ballVelocity.x =- ballVelocity.x; } if(ball.frame.origin.y + 35 > window.frame.size.height || ball.frame.origin.y < 0) { ballVelocity.y =- ballVelocity.y; } } } - (void)keyDown:(NSEvent *)theEvent { NSLog(@"habba"); // Arrow keys are associated with the numeric keypad if ([theEvent modifierFlags] & NSNumericPadKeyMask) { [window interpretKeyEvents:[NSArray arrayWithObject:theEvent]]; } else { [window keyDown:theEvent]; } } - (void)dealloc { [ball release]; [rightPaddle release]; [leftPaddle release]; [super dealloc]; } @end

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  • nhibernate fluent repository pattern insert problem

    - by voam
    I am trying to use Fluent NHibernate and the repository pattern. I would like my business layer to not be knowledgeable of the data persistence layer. Ideally I would pass in an initialized domain object to the insert method of the repository and all would be well. Where I run into problems is if the object being passed in has a child object. For example say I want to insert an a new order for a customer, and the customer is a property of the order object. I would like to do something like this: Customer c = new Customer; c.CustomerId = 1; Order o = new Order; o.Customer = c; repository.InsertOrder(o); The problem is that using NHiberate the CustomerId field is only privately settable so I can not set it directly like this. so what I have ended up doing is have my repository have an interface of Order InsertOrder(int customerId) where all the foreign keys get passed in as parameters. Somehow this just doesn't seem right. The other approach was to use the NHibernate session variable to load a customer object in my business model and then have the order passed in to the repository but this defeats my persistence ignorance ideal. Should I throw this persistence ignorance out the window or am I missing something here? Thanks

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  • substitution cypher with different alphabet length

    - by seanizer
    I would like to implement a simple substitution cypher to mask private ids in URLs I know how my IDs will look like (combination of upperchase ascii, digits and underscore), and they will be rather long, as they are composed keys. I would like to use a longer alphabet to shorten the resulting codes (I'd like to use upper and lower case ascii letters, digits and nothing else). So my incoming alphabet would be [A-Z0-9_] (37 chars) and my outgoing alphabet would be [A-Za-z0-9] (62 chars) so a compression of almost 50% would be available. let's say my URLs look like this: /my/page/GFZHFFFZFZTFZTF_24_F34 and I want them to look like this instead: /my/page/Ft32zfegZFV5 Obviously both arrays would be shuffled to bring some random order in. This does not have to be secure. if someone figures it out: fine, but I don't want the scheme to be obvious. My desired solution would be to convert the string to an integer representation of radix 37, convert the radix to 62 and use the second alphabet to write out that number. is there any sample code available that does something similar? Integer.parseInt ( http://java.sun.com/javase/6/docs/api/java/lang/Integer.html#parseInt%28java.lang.String,%20int%29 ) has some similar logic, but it is hard-coded to use standard digit behavior Any hints? I am using java to implement this but code or pseudo-code in any other language is of course also helpful

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  • Comparing all values within a List against each other

    - by Kave
    I am a bit stuck here and can't think further. public struct CandidateDetail { public int CellX { get; set; } public int CellY { get; set; } public int CellId { get; set; } } var dic = new Dictionary<int, List<CandidateDetail>>(); How can I compare each CandidateDetail item against other CandidateDetail items within the same dictionary in the most efficient way? Example: There are three keys for the dictionary: 5, 6 and 1. Therefore we have three entries. now each of these key entries would have a List associated with. In this case let say each of these three numbers has exactly two CandidateDetails items within the list associated to each key. This means in other words we have two 5, two 6 and two 1 in different or in the same cells. I would like to know: if[5].1stItem.CellId == [6].1stItem.CellId = we got a hit. That means we have a 5 and a 6 within the same Cell if[5].2ndItem.CellId == [6].2ndItem.CellId = perfect. We found out that the other 5 and 6 are together within a different cell. if[1].1stItem.CellId == ... Now I need to check the 1 also against the other 5 and 6 to see if the one exists within the previous same two cells or not. Could a Linq expression help perhaps? I am quite stuck here... I don't know...Maybe I am taking the wrong approach. I am trying to solve the "Hidden pair" of the game Sudoku. :) http://www.sudokusolver.eu/ExplainSolveMethodD.aspx Many Thanks, Kave

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  • Why are my Flex resource bundles not being loaded?

    - by Chris R
    I have an Actionscript module in the flex source folder filterModules, which is one of two additional source folders in my project (the main source folder is reports, but I'm not dealing with anything in there right now). Here's the MXML content that references the resources. ... This array is assigned to the dataProvider field of a ComboBox. It's not bound using the bindings, presumably for reasons that made sense to the original developer, and it'd be nontrivial to change the class to make that happen. I additionally have a resource property file in a folder resources/en_US and I have the source folder resources/{locale} in the project source settings. My additional compiler options are -locale en_US. The resource property file is resources/en_US/labels.properties (All paths are relative to the flash builder project root) and contains (amongst other things) these keys: metric.q3 = Overall Satisfaction metric.q5 = Personnel metric.q9a = Issue Resolution metric.q42 = Visit Duration Sat metric.q34 = Visit Duration I have written some FlexUnit tests that run in my local Flash Player that exercise these resources -- they check that every label is represented in the metrics array, for example, so I know that the resource file is loaded when run locally. However, when I copy the module .swf file over to my server, the combo box to which the array is assigned is empty. I copy the .swf like so, if it matters: rsync -rlDv --inplace -T /tmp ~/projects/flex_reports/bin-debug/rankingFilter.swf HOSTNAME:WEBROOT/flashPath/ Why is this? I am not able to debug the remote module because our surrounding site sets up a lot of context and makes some database calls to determine which module to load. I'm hoping to get some pointers on why resource bundles might not show up. I'd understand it if the array was present with wrong labels, but the array is instead completely empty, which is pretty odd.

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  • Can I delay the keyup event for jquery?

    - by Paul
    I'm using the rottentomatoes movie API in conjunction with twitter's typeahead plugin using bootstrap 2.0. I've been able to integerate the API but the issue I'm having is that after every keyup event the API gets called. This is all fine and dandy but I would rather make the call after a small pause allowing the user to type in several characters first. Here is my current code that calls the API after a keyup event: var autocomplete = $('#searchinput').typeahead() .on('keyup', function(ev){ ev.stopPropagation(); ev.preventDefault(); //filter out up/down, tab, enter, and escape keys if( $.inArray(ev.keyCode,[40,38,9,13,27]) === -1 ){ var self = $(this); //set typeahead source to empty self.data('typeahead').source = []; //active used so we aren't triggering duplicate keyup events if( !self.data('active') && self.val().length > 0){ self.data('active', true); //Do data request. Insert your own API logic here. $.getJSON("http://api.rottentomatoes.com/api/public/v1.0/movies.json?callback=?&apikey=MY_API_KEY&page_limit=5",{ q: encodeURI($(this).val()) }, function(data) { //set this to true when your callback executes self.data('active',true); //Filter out your own parameters. Populate them into an array, since this is what typeahead's source requires var arr = [], i=0; var movies = data.movies; $.each(movies, function(index, movie) { arr[i] = movie.title i++; }); //set your results into the typehead's source self.data('typeahead').source = arr; //trigger keyup on the typeahead to make it search self.trigger('keyup'); //All done, set to false to prepare for the next remote query. self.data('active', false); }); } } }); Is it possible to set a small delay and avoid calling the API after every keyup?

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  • Fastest way to convert a list of doubles to a unique list of integers?

    - by javanix
    I am dealing with a MySQL table here that is keyed in a somewhat unfortunate way. Instead of using an auto increment table as a key, it uses a column of decimals to preserve order (presumably so its not too difficult to insert new rows while preserving a primary key and order). Before I go through and redo this table to something more sane, I need to figure out how to rekey it without breaking everything. What I would like to do is something that takes a list of doubles (the current keys) and outputs a list of integers (which can be cast down to doubles for rekeying). For example, input {1.00, 2.00, 2.50, 2.60, 3.00} would give output {1, 2, 3, 4, 5). Since this is a database, I also need to be able to update the rows nicely: UPDATE table SET `key`='3.00' WHERE `key`='2.50'; Can anyone think of a speedy algorithm to do this? My current thought is to read all of the doubles into a vector, take the size of the vector, and output a new vector with values from 1 => doubleVector.size. This seems pretty slow, since you wouldn't want to read every value into the vector if, for instance, only the last n/100 elements needed to be modified. I think there is probably something I can do in place, since only values after the first non-integer double need to be modified, but I can't for the life of me figure anything out that would let me update in place as well. For instance, setting 2.60 to 3.00 the first time you see 2.50 in the original key list would result in an error, since the key value 3.00 is already used for the table.

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  • Get the key and value of Map that is used Inside another Map (JAVA)

    - by Umair Iqbal
    I am using a map inside another map, The key of the outer map is Integer and the value is another Map. I get the values as expected but I don't know how to get the key and value of teh inner map. Here is the code Map<Integer, Map<Integer, Integer>> cellsMap = new HashMap<Integer, Map<Integer, Integer>>(); Map<Integer , Integer> bandForCell = cellsMap.get(band_number); if (bandForCell == null) bandForCell = new HashMap<Integer, Integer>(); bandForCell.put(erfcn, cell_found); cellsMap.put(band_number, bandForCell); csv.writeCells((Map<Integer, Map<Integer, Integer>>) cellsMap); public void writeCells (Map<Integer, Map<Integer, Integer>> cellsMap ) throws IOException { for (Map.Entry<Integer, Map<Integer, Integer>> entry : cellsMap.entrySet()) { System.out.println("Key: " + entry.getKey() + ". Value: " + entry.getValue() + "\n"); } } Out put of my Map Key: 20 Value: {6331=0, 6330=1, 6329=1, 6328=0, 6335=1, 6437=0, 6436=1} The value in the above output is another map. How can I get the key and value of the inner map from the value of the outer map? Like Keys of inner map = 6331, 6330, 6329 .... and values of inner map = 0 , 1 , 1 , 0 ... Thanks

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  • Why are symbols not frozen strings?

    - by Alex Chaffee
    I understand the theoretical difference between Strings and Symbols. I understand that Symbols are meant to represent a concept or a name or an identifier or a label or a key, and Strings are a bag of characters. I understand that Strings are mutable and transient, where Symbols are immutable and permanent. I even like how Symbols look different from Strings in my text editor. What bothers me is that practically speaking, Symbols are so similar to Strings that the fact that they're not implemented as Strings causes a lot of headaches. They don't even support duck-typing or implicit coercion, unlike the other famous "the same but different" couple, Float and Fixnum. The mere existence of HashWithIndifferentAccess, and its rampant use in Rails and other frameworks, demonstrates that there's a problem here, an itch that needs to be scratched. Can anyone tell me a practical reason why Symbols should not be frozen Strings? Other than "because that's how it's always been done" (historical) or "because symbols are not strings" (begging the question). Consider the following astonishing behavior: :apple == "apple" #=> false, should be true :apple.hash == "apple".hash #=> false, should be true {apples: 10}["apples"] #=> nil, should be 10 {"apples" => 10}[:apples] #=> nil, should be 10 :apple.object_id == "apple".object_id #=> false, but that's actually fine All it would take to make the next generation of Rubyists less confused is this: class Symbol < String def initialize *args super self.freeze end (and a lot of other library-level hacking, but still, not too complicated) See also: http://onestepback.org/index.cgi/Tech/Ruby/SymbolsAreNotImmutableStrings.red http://www.randomhacks.net/articles/2007/01/20/13-ways-of-looking-at-a-ruby-symbol Why does my code break when using a hash symbol, instead of a hash string? Why use symbols as hash keys in Ruby? What are symbols and how do we use them? Ruby Symbols vs Strings in Hashes Can't get the hang of symbols in Ruby

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  • How do I simulate "In" using Linq2Sql

    - by flipdoubt
    I often find myself with a list of disconnected Linq2Sql objects or keys that I need to re-select from a Linq2Sql data-context to update or delete in the database. If this were SQL, I would use IN in the SQL WHERE clause, but I am stuck with what to do in Linq2Sql. Here is a sample of what I would like to write: public void MarkValidated(IList<int> idsToValidate) { using(_Db.NewSession()) // Instatiates new DataContext { // ThatAreIn <- this is where I am stuck var items = _Db.Items.ThatAreIn(idsToValidate).ToList(); foreach(var item in items) item.Validated = DateTime.Now; _Db.SubmitChanges(); } // Disposes of DataContext } Or: public void DeleteItems(IList<int> idsToDelete) { using(_Db.NewSession()) // Instatiates new DataContext { // ThatAreIn <- this is where I am stuck var items = _Db.Items.ThatAreIn(idsToValidate); _Db.Items.DeleteAllOnSubmit(items); _Db.SubmitChanges(); } // Disposes of DataContext } Can I get this done in one trip to the database? If so, how? Is it possible to send all those ints to the database as a list of parameters and is that more efficient than doing a foreach over the list to select each item one at a time?

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  • MySQL Normalization stored procedure performance

    - by srkiNZ84
    Hi, I've written a stored procedure in MySQL to take values currently in a table and to "Normalize" them. This means that for each value passed to the stored procedure, it checks whether the value is already in the table. If it is, then it stores the id of that row in a variable. If the value is not in the table, it stores the newly inserted value's id. The stored procedure then takes the id's and inserts them into a table which is equivalent to the original de-normailized table, but this table is fully normalized and consists of mainly foreign keys. My problem with this design is that the stored procedure takes approximately 10ms or so to return, which is too long when you're trying to work through some 10million records. My suspicion is that the performance is to do with the way in which I'm doing the inserts. i.e. INSERT INTO TableA (first_value) VALUES (argument_from_sp) ON DUPLICATE KEY UPDATE id=LAST_INSERT_ID(id); SET @TableAId = LAST_INSERT_ID(); The "ON DUPLICATE KEY UPDATE" is a bit of a hack, due to the fact that on a duplicate key I don't want to update anything but rather just return the id value of the row. If you miss this step though, the LAST_INSERT_ID() function returns the wrong value when you're trying to run the "SET ..." statement. Does anyone know of a better way to do this in MySQL? Thank you

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  • PHP / Zend Framework: Force prepend table name to column name in result array?

    - by Brian Lacy
    I am using Zend_Db_Select currently to retrieve hierarchical data from several joined tables. I need to be able to convert this easily into an array. Short of using a switch statement and listing out all the columns individually in order to sort the data, my thought was that if I could get the table names auto-prepended to the keys in the result array, that would solve my problem. So considering the following (assembled) SQL: SELECT user.*, contact.* FROM user INNER JOIN contact ON contact.user_id = user.user_id I would normally get a result array like this: [username] => 'bob', [contact_id] => 5, [user_id] => 2, [firstname] => 'bob', [lastname] => 'larsen' But instead I want this: [user.user_id] => 2, [user.username] => 'bob', [contact.contact_id] => 5, [contact.firstname] => 'bob', [contact.lastname] => 'larsen' Does anyone have an idea how to achieve this? Thanks!

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  • Hadoop/MapReduce: Reading and writing classes generated from DDL

    - by Dave
    Hi, Can someone walk me though the basic work-flow of reading and writing data with classes generated from DDL? I have defined some struct-like records using DDL. For example: class Customer { ustring FirstName; ustring LastName; ustring CardNo; long LastPurchase; } I've compiled this to get a Customer class and included it into my project. I can easily see how to use this as input and output for mappers and reducers (the generated class implements Writable), but not how to read and write it to file. The JavaDoc for the org.apache.hadoop.record package talks about serializing these records in Binary, CSV or XML format. How do I actually do that? Say my reducer produces IntWritable keys and Customer values. What OutputFormat do I use to write the result in CSV format? What InputFormat would I use to read the resulting files in later, if I wanted to perform analysis over them?

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  • EasyHook Windows Hooking problem/.dll injection

    - by Tom
    Ok can someone try and find the error with this code, it should produce all the registry keys every time something accesses them but i keep getting: System.MissingMethodException: The given method does not exist at EasyHook.LocalHook.GetProcAdress(String InModule, String InChannelName) An example code can be found here: http://www.codeproject.com/KB/DLL/EasyHook64.aspx I can get the CcreateFileW example to work! My code is here: public class Main : EasyHook.IEntryPoint { FileMon.FileMonInterface Interface; LocalHook LocalHook; Stack<String> Queue = new Stack<String>(); public Main(RemoteHooking.IContext InContext,String InChannelName) { // connect to host... Interface = RemoteHooking.IpcConnectClient<FileMon.FileMonInterface>(InChannelName); Interface.Ping(); } public void Run(RemoteHooking.IContext InContext,String InChannelName) { // install hook... try { LocalHook localHook = LocalHook.Create(LocalHook.GetProcAddress("Advapi32.dll", "RegOpenKeyExW"),new DMyRegOpenKeyExW(MyRegOpenKeyExW),this); localHook.ThreadACL.SetExclusiveACL(new int[] { }); } catch (Exception ExtInfo) { Interface.ReportException(ExtInfo); return; } Interface.IsInstalled(RemoteHooking.GetCurrentProcessId()); RemoteHooking.WakeUpProcess(); // wait for host process termination... try { while (true) { Thread.Sleep(500); // transmit newly monitored file accesses... if (Queue.Count > 0) { String[] Package = null; lock (Queue) { Package = Queue.ToArray(); Queue.Clear(); } Interface.OnCreateFile(RemoteHooking.GetCurrentProcessId(), Package); } else Interface.Ping(); } } catch { // Ping() will raise an exception if host is unreachable } } [DllImport("Advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true, CallingConvention = CallingConvention.StdCall)] static extern int RegOpenKeyExW(UIntPtr hKey,string subKey,int ulOptions,int samDesired,out UIntPtr hkResult); [UnmanagedFunctionPointer(CallingConvention.StdCall, CharSet = CharSet.Unicode, SetLastError = true)] delegate int DMyRegOpenKeyExW(UIntPtr hKey,string subKey,int ulOptions,int samDesired,out UIntPtr hkResult); int MyRegOpenKeyExW(UIntPtr hKey,string subKey,int ulOptions,int samDesired,out UIntPtr hkResult) { Console.WriteLine(string.Format("Accessing: {0}", subKey)); return RegOpenKeyExW(hKey, subKey, ulOptions, samDesired, out hkResult); } }

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