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  • Image rotate opecv error

    - by avd
    When I use this code to rotate the image, the destination image size remains same and hence the image gets clipped. Please provide me a way/code snippet to resize accordingly (like matlab does in imrotate) so that image does not get clipped and outlier pixels gets filled with all white instead of black. void imrotate(std::string imgPath,std::string angleStr,std::string outPath) { size_t found1,found2; found1=imgPath.find_last_of('/'); found2=imgPath.size()-4; IplImage* src=cvLoadImage(imgPath.c_str(), -1);; IplImage* dst; dst = cvCloneImage( src ); int angle = atoi(angleStr.c_str()); CvMat* rot_mat = cvCreateMat(2,3,CV_32FC1); CvPoint2D32f center = cvPoint2D32f( src->width/2, src->height/2 ); double scale = 1; cv2DRotationMatrix( center, angle, scale, rot_mat ); cvWarpAffine( src, dst, rot_mat); char angStr[4]; sprintf(angStr,"%d",angle); cvSaveImage(string(outPath+imgPath.substr(found1+1,found2-found1-1)+"_"+angStr+".jpg").c_str(),dst); cvReleaseImage(&src); cvReleaseImage(&dst); cvReleaseMat( &rot_mat ); } Original Image: Rotated Image:

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  • PHP syntax for postgresql Mixed-case table names

    - by yam
    I have a code below: <?php require "institution.php" /* in this portion, query for database connection is executed, and */ $institution= $_POST['institutionname']; $sCampID = 'SELECT ins_id FROM institution where ins_name= '$institution' '; $qcampID = pg_query($sCampID) or die("Error in query: $query." . pg_last_error($connection)); /* this portion outputs the ins_id */ ?> My database before has no mixed-case table names, that's why when I run this query, it shows no error at all. But because I've changed my database for some reasons, and it contains now mixed-case table names, i have to change the code above into this one: $sCampID = 'SELECT ins_id FROM "Institution" where ins_name= '$institution' '; where the Institution has to be double quoted. The query returned parse error. When i removed this portion: where ins_name= '$institution', no error occured. My question is how do I solve this problem where the table name which contains a mixed-case letter and a value stored in a variable ($institution in this case) will be combined in a single select statement? Your answers and suggestions will be very much appreciated.

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  • How can i design a DB where the user can define the fields and types of a detail table in a M-D rela

    - by Simon
    My application has one table called 'events' and each event has approx 30 standard fields, but also user defined fields that could be any name or type, in an 'eventdata' table. Users can define these event data tables, by specifying x number of fields (either text/double/datetime/boolean) and the names of these fields. This 'eventdata' (table) can be different for each 'event'. My current approach is to create a lookup table for the definitions. So if i need to query all 'event' and 'eventdata' per record, i do so in a M-D relaitionship using two queries (i.e. select * from events, then for each record in 'events', select * from 'some table'). Is there a better approach to doing this? I have implemented this so far, but most of my queries require two distinct calls to the DB - i cannot simply join my master 'events' table with different 'eventdata' tables for each record in in 'events'. I guess my main question is: can i join my master table with different detail tables for each record? E.g. SELECT E.*, E.Tablename FROM events E LEFT JOIN 'E.tablename' T ON E._ID = T.ID If not, is there a better way to design my database considering i have no idea on how many user defined fields there may be and what type they will be.

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  • Javascript ( jQuery ) Error: SyntaxError: missing ) after argument list

    - by Obmerk Kronen
    I have the simplest function : jQuery(document).ajaxSuccess(function(e, xhr, settings) { var widget_id_base = '099_cf_samurai_widget'; if(settings.data.search('action=save-widget') != -1 && settings.data.search('id_base=' + widget_id_base) != -1) { // alert(\'yay!'\); my_function_chosen_099(); } }); function my_function_chosen_099(){ jQuery(".chzn-select").chosen(); } which works just fine , but When I add the width Parameter like so : function my_function_chosen_k99(){ jQuery(".chzn-select").chosen(width:'95%'); } it gives me an error of: Error: SyntaxError: missing ) after argument list Source File: http://localhost/my-path/js/o99.chosen.init.js?ver=k99 Line: 20, Column: 41 Source Code: jQuery(".chzn-select").chosen(width:"95%"); .............................................| I have tried escaping: jQuery(".chzn-select").chosen(width:\"95%"\); and even double jQuery(".chzn-select").chosen(width:\\"95%"\\); and in my desperation, even jQuery(".chzn-select").chosen( width:"95%" ); I checked and rechecked the closing of brackets , and also tried with single quotes ' - but nothing . There appear to be a lot of similar questions here , but all I saw was escaping problems, ANd I have tried all that I know .. What is wrong here ?? I assume it is not a simple syntax error - or is it ? ( one which I can not find .. )

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  • Regex to GENERATE thumbnails!?!?! (but that's crazy!)

    - by CryptoMonkey
    Hello everyone! So here is my situation, and the solution that I've come up with to solve the problem. I have created an application that includes TinyMCE to allow users to create HTML content for publishing. The user can include images in their markup, and drag/resize those images effecting the final Width/Height attributes in the IMG tag. This is all great, the users can include images and resize/relocate them to their desired appearance. But one big problem is that I am now sending a (possibly) much larger image to the client, only to have the browser resize the image into the requested Width/Height attributes. All that bandwidth and lost load time.... So my solution is to pre-process my users markup content, scanning all of the IMG tags and parsing out the Height/Width/Src attributes. Then set each img's SRC tag to a phpThumb request with the parsed Height/Width passed into the thumbnails URL. This will create my reduced size image (optimising bandwidth at the expense of CPU and caching). What do you think about this solution? I've seen other posts where people were using mod_rewrite to do something similar, but I want to effect the content on the page service and not manipulate the image requests as they're being received. .... Any thoughts about this design? I need some help with the fine details as my regex skills need some work, but I'm very short on time and promise to pay my technical knowledge debt soon. To make the regex's easier, I can be sure of some things. Only img tags that need this processing will have an existing width="" height="" attributes (with the double quotes, and lower cased text, but I suppose matching the text case insensitive would be better if TinyMCE changes) So a regex to match only the necessary Img tags, and maybe another three regex's to extract the src, the width, and the height? Thanks everyone.

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  • Can anyone provide a good "idiot's guide" to creating an installer in VS2008 (C#) Pro?

    - by paxdiablo
    I have Visual C# 2008 Professional and have developed the first half of a C# application (console mode) with the second half in progress now (GUI). I'm looking for an easy path to creating an installer for it. What are the steps that need to be taken to produce a professional installer? There's a similar question here regarding the Express edition but I have Pro, and I would like as much as possible to stick with just the standard VS stuff (if you think you can convince me that a third party installer creator is much better than a VS-only solution, give it a shot, by all means). Keep in mind that I have no interest in upgrading to VS2010 yet, even if it's a hundred times easier to create an installer. That can come later, when the revenue starts rolling in :-) Also be aware that the GUI component of this application is a totally separate executable from the console part. The console part is a simple "open file 1, do some work on it, write file 2" type and the GUI is a fairly standard "open file, do some stuff" beast so there's no tricky or wildly undocumented behaviour happening. Basically, I'm looking for (at least) the following: professional looking installer. ability to specify where the application files go. changes to the registry to allow double-clicks on my file extension to open the GUI app with the file as an argument. needs to install everything required (my stuff, .Net if required, and so on).

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  • Making firefox refresh images faster

    - by Earlz
    I have a thing I'm doing where I need a webpage to stream a series of images from the local client computer. I have a very simple run here: http://jsbin.com/idowi/34 The code is extremely simple setTimeout ( "refreshImage()", 100 ); function refreshImage(){ var date = new Date() var ticks = date.getTime() $('#image').attr('src','http://127.0.0.1:2723/signature?'+ticks.toString()); setTimeout ("refreshImage()", 100 ); } Basically I have a signature pad being used on the client machine. We want for the signature to show up in the web page and for them to see themselves signing it within the web page(the pad does not have an LCD to show it to them right there). So I setup a simple local HTTP server which grabs an image of what the current state of the signature pad looks like and it gets sent to the browser. This has no problems in any browser(tested in IE7, 8, and Chrome) but Firefox where it is extremely laggy and jumpy and doesn't keep with the 10 FPS rate. Does anyone have any ideas on how to fix this? I've tried creating very simple double buffering in javascript but that just made things worse. Also for a bit more information it seems that Firefox is executing the javascript at the correct framerate as on the server the requests are coming in at a constant speed. But the images are only refreshed inconsistently ranging from 5 times per second all the way down to 0 times per second(taking 2 seconds to do a refresh) Also I have tried using different image formats all with the same results. The formats I've tried include bitmaps, PNGs, and GIFs (GIFs caused a minor problem in Chrome with flicker though) Could it be possible that Firefox is somehow caching my images causing a slight lag? I send these headers though: Pragma-directive: no-cache Cache-directive: no-cache Cache-control: no-cache Pragma: no-cache Expires: 0

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  • Find out when all processes in (void) is done?

    - by Emil
    Hey. I need to know how you can find out when all processes (loaded) from a - (void) are done, if it's possible. Why? I'm loading in data for a UITableView, and I need to know when a Loading... view can be replaced with the UITableView, and when I can start creating the cells. This is my code: - (void) reloadData { NSAutoreleasePool *releasePool = [[NSAutoreleasePool alloc] init]; NSLog(@"Reloading data."); NSURL *urlPosts = [NSURL URLWithString:[NSString stringWithFormat:@"%@", URL]]; NSError *lookupError = nil; NSString *data = [[NSString alloc] initWithContentsOfURL:urlPosts encoding:NSUTF8StringEncoding error:&lookupError]; postsData = [data componentsSeparatedByString:@"~"]; [data release], data = nil; urlPosts = nil; self.numberOfPosts = [[postsData objectAtIndex:0] intValue]; self.postsArrayID = [[postsData objectAtIndex:1] componentsSeparatedByString:@"#"]; self.postsArrayDate = [[postsData objectAtIndex:2] componentsSeparatedByString:@"#"]; self.postsArrayTitle = [[postsData objectAtIndex:3] componentsSeparatedByString:@"#"]; self.postsArrayComments = [[postsData objectAtIndex:4] componentsSeparatedByString:@"#"]; self.postsArrayImgSrc = [[postsData objectAtIndex:5] componentsSeparatedByString:@"#"]; NSMutableArray *writeToPlist = [NSMutableArray array]; NSMutableArray *writeToNoImagePlist = [NSMutableArray array]; NSMutableArray *imagesStored = [NSMutableArray arrayWithContentsOfFile:[rootPath stringByAppendingPathComponent:@"imagesStored.plist"]]; int loop = 0; for (NSString *postID in postsArrayID) { if ([imagesStored containsObject:[NSString stringWithFormat:@"%@.png", postID]]){ NSLog(@"Allready stored, jump to next. ID: %@", postID); continue; } NSLog(@"%@.png", postID); NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:[postsArrayImgSrc objectAtIndex:loop]]]; // If image contains anything, set cellImage to image. If image is empty, try one more time or use noImage.png, set in IB if (imageData == nil){ NSLog(@"imageData is empty before trying .jpeg"); // If image == nil, try to replace .jpg with .jpeg, and if that worked, set cellImage to that image. If that is also nil, use noImage.png, set in IB. imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:[[postsArrayImgSrc objectAtIndex:loop] stringByReplacingOccurrencesOfString:@".jpg" withString:@".jpeg"]]]; } if (imageData != nil){ NSLog(@"imageData is NOT empty when creating file"); [fileManager createFileAtPath:[rootPath stringByAppendingPathComponent:[NSString stringWithFormat:@"images/%@.png", postID]] contents:imageData attributes:nil]; [writeToPlist addObject:[NSString stringWithFormat:@"%@.png", postID]]; } else { [writeToNoImagePlist addObject:[NSString stringWithFormat:@"%@", postID]]; } imageData = nil; loop++; NSLog(@"imagePlist: %@\nnoImagePlist: %@", writeToPlist, writeToNoImagePlist); } NSMutableArray *writeToAllPlist = [NSMutableArray arrayWithArray:writeToPlist]; [writeToPlist addObjectsFromArray:[NSArray arrayWithContentsOfFile:nowPlist]]; [writeToAllPlist addObjectsFromArray:[NSArray arrayWithContentsOfFile:[rootPath stringByAppendingPathComponent:@"imagesStored.plist"]]]; [writeToNoImagePlist addObjectsFromArray:[NSArray arrayWithContentsOfFile:[rootPath stringByAppendingPathComponent:@"noImage.plist"]]]; [writeToPlist writeToFile:nowPlist atomically:YES]; [writeToAllPlist writeToFile:[rootPath stringByAppendingPathComponent:@"imagesStored.plist"] atomically:YES]; [writeToNoImagePlist writeToFile:[rootPath stringByAppendingPathComponent:@"noImage.plist"] atomically:YES]; [releasePool release]; }

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  • Calculating percent "x/y * 100" always results in 0?

    - by Patrick Beninga
    In my assignment i have to make a simple version of Craps, for some reason the percentage assignments always produce 0 even when both variables are non 0, here is the code. import java.util.Random; Header, note the variables public class Craps { private int die1, die2,myRoll ,myBet,point,myWins,myLosses; private double winPercent,lossPercent; private Random r = new Random(); Just rolls two dies and produces their some. public int roll(){ die1 = r.nextInt(6)+1; die2 = r.nextInt(6)+1; return(die1 + die2); } The Play method, this just loops through the game. public void play(){ myRoll = roll(); point = 0; if(myRoll == 2 ||myRoll == 3 || myRoll == 12){ System.out.println("You lose!"); myLosses++; }else if(myRoll == 7 || myRoll == 11){ System.out.println("You win!"); myWins++; }else{ point = myRoll; do { myRoll = roll(); }while(myRoll != 7 && myRoll != point); if(myRoll == point){ System.out.println("You win!"); myWins++; }else{ System.out.println("You lose!"); myLosses++; } } } This is where the bug is, this is the tester method. public void tester(int howMany){ int i = 0; while(i < howMany){ play(); i++; } bug is right here in these assignments statements winPercent = myWins/i * 100; lossPercent = myLosses/i* 100; System.out.println("program ran "+i+" times "+winPercent+"% wins "+ lossPercent+"% losses with "+myWins+" wins and "+myLosses+" losses"); } }

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  • Set registry to control working dir when associating file-type with application

    - by John
    I'm using Inno for an installer, and I want to associate a file type with my app: Root: HKCR; Subkey: ".rpl"; ValueType: string; ValueName: ""; ValueData: "MyReplay"; Flags: uninsdeletevalue; Root: HKCR; Subkey: "MyReplay"; ValueType: string; ValueName: ""; ValueData: "Replay File"; Flags: uninsdeletekey; Root: HKCR; Subkey: "MyReplay\DefaultIcon"; ValueType: string; ValueName: ""; ValueData: "{app}\bin\MyApp.ico,0"; Flags: uninsdeletekey; Root: HKCR; Subkey: "MyReplay\shell\open\command"; ValueType: string; ValueName: ""; ValueData: """{app}\bin\MyApp.exe"" ""%1"""; Flags: uninsdeletekey; Right now, double-clicking a .rpl file launches the app, but the working dir appears to be where the .rpl file is located, so the app crashes as it can't load any data. Is it posible to set the registry to control the start/working dir for file associations as well as the app that is launched? Or does my app itself need to be able to work around this?

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  • C++ ulong to class method pointer and back

    - by Simone Margaritelli
    Hi guys, I'm using a hash table (source code by Google Inc) to store some method pointers defined as: typedef Object *(Executor::*expression_delegate_t)( vframe_t *, Node * ); Where obviously "Executor" is the class. The function prototype to insert some value to the hash table is: hash_item_t *ht_insert( hash_table_t *ht, ulong key, ulong data ); So basically i'm doing the insert double casting the method pointer: ht_insert( table, ASSIGN, reinterpret_cast<ulong>( (void *)&Executor::onAssign ) ); Where table is defined as a 'hash_table_t *' inside the declaration of the Executor class, ASSIGN is an unsigned long value, and 'onAssign' is the method I have to map. Now, Executor::onAssign is stored as an unsigned long value, its address in memory I think, and I need to cast back the ulong to a method pointer. But this code: hash_item_t* item = ht_find( table, ASSIGN ); expression_delegate_t delegate = reinterpret_cast < expression_delegate_t > (item->data); Gives me the following compilation error : src/executor.cpp:45: error: invalid cast from type ‘ulong’ to type ‘Object* (Executor::*)(vframe_t*, Node*)’ I'm using GCC v4.4.3 on a x86 GNU/Linux machine. Any hints?

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  • C++ std::vector memory/allocation

    - by aaa
    from a previous question about vector capacity, http://stackoverflow.com/questions/2663170/stdvector-capacity-after-copying, Mr. Bailey said: In current C++ you are guaranteed that no reallocation occurs after a call to reserve until an insertion would take the size beyond the value of the previous call to reserve. Before a call to reserve, or after a call to reserve when the size is between the value of the previous call to reserve and the capacity the implementation is allowed to reallocate early if it so chooses. So, if I understand correctly, in order to assure that no relocation happens until capacity is exceeded, I must do reserve twice? can you please clarify it? I am using vector as a memory stack like this: std::vector<double> memory; memory.reserve(size); memory.insert(memory.end(), matrix.data().begin(), matrix.data().end()); // smaller than size size_t offset = memory.size(); memory.resize(memory.capacity(), 0); I need to guarantee that relocation does not happen in the above. thank you. ps: I would also like to know if there is a better way to manage memory stack in similar manner other than vector

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  • calculating change (over a period) for a dated field

    - by morpheous
    I have two tables with the following schema: CREATE TABLE sales_data ( sales_time date NOT NULL, product_id integer NOT NULL, sales_amt double NOT NULL ); CREATE TABLE date_dimension ( id integer NOT NULL, datestamp date NOT NULL, day_part integer NOT NULL, week_part integer NOT NULL, month_part integer NOT NULL, qtr_part integer NOT NULL, year_part integer NOT NULL, ); I want to write two types of queries that will allow me to calculate: period on period change (e.g. week on week change) change in period on period change (e.g. change in week on week change) I would prefer to write this in ANSI SQL, since I dont want to be tied to any particular db. [Edit] In light of some of the comments, if I have to be tied to a single database (in terms of SQL dialect), it will have to be PostgreSQL The queries I want to write are of the form (pseudo SQL of course): Query Type 1 (Period on Period Change) ======================================= a). select product_id, ((sd2.sales_amt - sd1.sales_amt)/sd1.sales_amt) as week_on_week_change from sales_data sd1, sales_data sd2, date_dimension dd where {SOME CRITERIA) b). select product_id, ((sd2.sales_amt - sd1.sales_amt)/sd1.sales_amt) as month_on_month_change from sales_data sd1, sales_data sd2, date_dimension dd where {SOME CRITERIA) Query Type 2 (Change in Period on Period Change) ================================================= a). select product_id, ((a2.week_on_week_change - a1.week_on_week_change)/a1.week_on_week_change) as change_on_week_on_week_change from (select product_id, ((sd2.sales_amt - sd1.sales_amt)/sd1.sales_amt) as week_on_week_change from sales_data sd1, sales_data sd2, date_dimension dd where {SOME CRITERIA) as a1), (select product_id, ((sd2.sales_amt - sd1.sales_amt)/sd1.sales_amt) as week_on_week_change from sales_data sd1, sales_data sd2, date_dimension dd where {SOME CRITERIA) as a2) WHERE {SOME OTHER CRITERIA}

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  • (Java) Get value of string loaded into dynamic-type object?

    - by Michael
    I'm very new to Java (~10 days), so my code is probably pretty bad, but here's what I've got: ArgsDataHolder argsData = new ArgsDataHolder(); // a class that holds two // ArrayList's where each element // representing key/value args Class thisArgClass; String thisArgString; Object thisArg; for(int i=2; i< argsString.length; i++) { thisToken = argsString[i]; thisArgClassString = getClassStringFromToken(thisToken).toLowerCase(); System.out.println("thisArgClassString: " + thisArgClassString); thisArgClass = getClassFromClassString(thisArgClassString); // find closing tag; concatenate middle Integer j = new Integer(i+1); thisArgString = getArgValue(argsString, j, "</" + thisArgClassString + ">"); thisArg = thisArgClass.newInstance(); thisArg = thisArgClass.valueOf(thisArgString); argsData.append(thisArg, thisArgClass); } The user basically has to input a set of key/value arguments into the command prompt in this format: <class>value</class>, e.g. <int>62</int>. Using this example, thisArgClass would be equal to Integer.class, thisArgString would be a string that read "62", and thisArg would be an instance of Integer that is equal to 62. I tried thisArg.valueOf(thisArgString), but I guess valueOf(<String>) is only a method of certain subclasses of Object. For whatever reason, I can't seem to be able to cast thisArg to thisArgClass (like so: thisArg = (thisArgClass)thisArgClass.newInstance();, at which point valueOf(<String>) should become accessible. There's got to be a nice, clean way of doing this, but it is beyond my abilities at this point. How can I get the value of the string loaded into a dynamically-typed object (Integer, Long, Float, Double, String, Character, Boolean, etc.)? Or am I just overthinking this, and Java will do the conversion for me? :confused:

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  • expected identifier or '(' before '{' token in Flex

    - by user1829177
    I am trying to use Flex to parse 'C' source code. Unfortunately I am getting the error "expected identifier or '(' before '{' token" on lines 1,12,13,14... . Any ideas why? %{ %} digit [0-9] letter [a-zA-Z] number (digit)+ id (letter|_)(letter|digit|_)* integer (int) character (char) comma [,] %% {integer} {return INT;} {character} {return CHAR;} {number} {return NUM;} {id} {return IDENTIFIER;} {comma} {return ',';} [-+*/] {return *yytext;} . {} %% main() { yylex(); } The corresponding flex file is as shown below: %{ #include <ctype.h> #include <stdio.h> #include "myhead.h" #include "mini.l" #define YYSTYPE double # undef fprintf %} %token INT %token CHAR %token IDENTIFIER %token NUM %token ',' %left '+' '-' %left '*' '/' %right UMINUS %% lines:lines expr '\n' {printf("%g\n",$2);} |lines '\n' |D | ; expr :expr '*' expr {$$=$1*$3;} |expr '/' expr {$$=$1/$3;} |expr '+' expr {$$=$1+$3;} |expr '-' expr {$$=$1+$3;} |'(' expr ')' {$$=$2;} |'-' expr %prec UMINUS {$$=-$2;} |IDENTIFIER {} |NUM {} ; T :INT {} |CHAR {} ; L :L ',' IDENTIFIER {} |IDENTIFIER {} ; D :T L {printf("T is %g, L is %g",$1,$2);} ; %% /*void yyerror (char *s) { fprintf (stderr, "%s\n", s); } */ I am compiling the generated code using the command: gcc my_file.c -ly

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  • C++ CRTP question

    - by aaa
    following piece of code does not compile, the problem is in T::rank not be inaccessible (I think) or uninitialized in parent template. Can you tell me exactly what the problem is? is passing rank explicitly the only way? or is there a way to query tensor class directly? Thank you #include <boost/utility/enable_if.hpp> template<class T, // size_t N, class enable = void> struct tensor_operator; // template<class T, size_t N> template<class T> struct tensor_operator<T, typename boost::enable_if_c< T::rank == 4>::type > { tensor_operator(T &tensor) : tensor_(tensor) {} T& operator()(int i,int j,int k,int l) { return tensor_.layout.element_at(i, j, k, l); } T &tensor_; }; template<size_t N, typename T = double> // struct tensor : tensor_operator<tensor<N,T>, N> { struct tensor : tensor_operator<tensor<N,T> > { static const size_t rank = N; }; I know the workaround, however am interested in mechanics of template instantiation for self-education

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  • ReplaceAll not working as expected

    - by Tim Kemp
    Still early days with Mathematica so please forgive what is probably a very obvious question. I am trying to generate some parametric plots. I have: ParametricPlot[{ (a + b) Cos[t] - h Cos[(a + b)/b t], (a + b) Sin[t] - h Sin[(a + b)/b t]}, {t, 0, 2 \[Pi]}, PlotRange -> All] /. {a -> 2, b -> 1, h -> 1} No joy: the replacement rules are not applied and a, b and h remain undefined. If I instead do: Hold@ParametricPlot[{ (a + b) Cos[t] - h Cos[(a + b)/b t], (a + b) Sin[t] - h Sin[(a + b)/b t]}, {t, 0, 2 \[Pi]}, PlotRange -> All] /. {a -> 2, b -> 1, h -> 1} it looks like the rules ARE working, as confirmed by the output: Hold[ParametricPlot[{(2 + 1) Cos[t] - 1 Cos[(2 + 1) t], (2 + 1) Sin[t] - 1 Sin[(2 + 1) t]}, {t, 0, 2 \[Pi]}, PlotRange -> All]] Which is what I'd expect. Take the Hold off, though, and the ParametricPlot doesn't work. There's nothing wrong with the equations or the ParametricPlot itself, though, because I tried setting values for a, b and h in a separate expression (a=2; b=1; h=1) and I get my pretty double cardoid out as expected. So, what am I doing wrong with ReplaceAll and why are the transformation rules not working? This is another fundamentally important aspect of MMA that my OOP-ruined brain isn't understanding. I tried reading up on ReplaceAll and ParametricPlot and the closest clue I found was that "ParametricPlot has attribute HoldAll and evaluates f only after assigning specific numerical values to variables" which didn't help much or I wouldn't be here. Thanks.

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  • I just wanted to DES 4096 bytes of data with a 128 bits key...

    - by badp
    ...and what the nice folks at OpenSSL gratiously provide me with is this. :) Now, since you shouldn't be guessing when using cryptography, I come here for confirmation: what is the function call I want to use? What I understood A 128 bits key is 16 byte large, so I'll need double DES (2 × 8 byte). This leaves me with only a few function calls: void DES_ede2_cfb64_encrypt(const unsigned char *in, unsigned char *out, long length, DES_key_schedule *ks1, DES_key_schedule *ks2, DES_cblock *ivec, int *num, int enc); void DES_ede2_cbc_encrypt(const unsigned char *input, unsigned char *output, long length, DES_key_schedule *ks1, DES_key_schedule *ks2, DES_cblock *ivec, int enc); void DES_ede2_cfb64_encrypt(const unsigned char *in, unsigned char *out, long length, DES_key_schedule *ks1, DES_key_schedule *ks2, DES_cblock *ivec, int *num, int enc); void DES_ede2_ofb64_encrypt(const unsigned char *in, unsigned char *out, long length, DES_key_schedule *ks1, DES_key_schedule *ks2, DES_cblock *ivec, int *num); In this case, I guess the function I want to call DES_ede2_cfb64_encrypt, although I'm not so sure -- I definitely don't need padding here and I'd have to care about what ivec and num are, and how I want to generate them... What am I missing?

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  • Changes to data inside class not being shown when accessed from outside class.

    - by Hypatia
    I have two classes, Car and Person. Car has as one of its members an instance of Person, driver. I want to move a car, while keeping track of its location, and also move the driver inside the car and get its location. However, while this works from inside the class (I have printed out the values as they are calculated), when I try to access the data from main, there's nothing there. I.e. the array position[] ends up empty. I am wondering if there is something wrong with the way I have set up the classes -- could it be a problem of the scope of the object? I have tried simplifying the code so that I only give what is necessary. Hopefully that covers everything that you would need to see. The constructer Car() fills the offset array of driver with nonzero values. class Car{ public: Container(float=0,float=0,float=0); ~Container(); void move(float); void getPosition(float[]); void getDriverPosition(float[]); private: float position[3]; Person driver; float heading; float velocity; }; class Person{ public: Person(float=0,float=0,float=0); ~Person(); void setOffset(float=0,float=0,float=0); void setPosition(float=0,float=0,float=0); void getOffset(float[]); void getPosition(float[]); private: float position[3]; float offset[3]; }; Some of the functions: void Car::move(float time){ float distance = velocity*time; location[0] += distance*cos(PI/2 - heading); location[1] += distance*sin(PI/2 - heading); float driverLocation [3]; float offset[3]; driver->getOffset(offset); for (int i = 0; i < 3; i++){ driverLocation[i] = offset[i] + location[i]; } } void Car::getDriverPosition(float p[]){ driver.getPosition(p); } void Person::getPosition(float p[]){ for (int i = 0; i < 3; i++){ p[i] = position[i]; } } void Person::getOffset(float o[]){ for (int i = 0; i < 3; i++){ o[i] = offset[i]; } } In Main: Car * car = new Car(); car->move(); float p[3]; car->getDriverPosition(p); When I print driverLocation[] inside the move() function, I have actual nonzero values. When I print p[] inside main, all I get are zeros.

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  • Export to csv, string w/ comma in it, splits it up

    - by Brad
    This code exports data into a csv file, which is opened within Excel. When a string has a comma within it, it messes up the order of the data. I need help modifying my code below to resolve any data that contains a comma within it, to not to create a new column. I am assuming it will pass each string within double quotes, so any comma within those quotes, then it will make an exception. Any help is appreciated. $result = mysql_query("select lname, fname, email, dtelephone, etelephone, contactwhen, comments, thursday, friday, saturday, sunday, monday FROM volunteers_2010"); $csv_output .= "Last Name,First Name,Email,Telephone (Day),Telephone (Evening),Contact When,Comments,Thursday,Friday,Saturday,Sunday,Monday,Comments\n"; $i = 0; if (mysql_num_rows($result) > 0) { while ($row = mysql_fetch_assoc($result)) { $csv_output .= $row['Field'].", "; $i++; } } $csv_output .= "\n"; $values = mysql_query("SELECT lname, fname, email, dtelephone, etelephone, contactwhen, comments, thursday, friday, saturday, sunday, monday FROM volunteers_2010 WHERE venue_id = $venue_id"); while ($rowr = mysql_fetch_row($values)) { for ($j=0;$j<$i;$j++) { $csv_output .= $rowr[$j].", "; } $csv_output .= "\n"; }

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  • write a program that prompts the user to input five decimal numbers

    - by user312309
    This is the question. write a program that prompts the user to input five decimal numbers. the program should then add the five decimal numbers, convert the sum to the nearest integer,m and print the result. This is what I've gotten so far: // p111n9.cpp : Defines the entry point for the console application. // #include <iostream> using namespace std; double a, b , c , d , e, f; int main(int argc, char* argv[]) { cout << "enter 5 decimals: " << endl; cin >> a >> b >> c >> d >> e; f = a + b + c + d + e; return 0; } Now I just need to convert the sum(f) to the nearest integer, m and print the result. How do I do this?

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  • Java: how to avoid circual references when dumping object information with reflection?

    - by Tom
    I've modified an object dumping method to avoid circual references causing a StackOverflow error. This is what I ended up with: //returns all fields of the given object in a string public static String dumpFields(Object o, int callCount, ArrayList excludeList) { //add this object to the exclude list to avoid circual references in the future if (excludeList == null) excludeList = new ArrayList(); excludeList.add(o); callCount++; StringBuffer tabs = new StringBuffer(); for (int k = 0; k < callCount; k++) { tabs.append("\t"); } StringBuffer buffer = new StringBuffer(); Class oClass = o.getClass(); if (oClass.isArray()) { buffer.append("\n"); buffer.append(tabs.toString()); buffer.append("["); for (int i = 0; i < Array.getLength(o); i++) { if (i < 0) buffer.append(","); Object value = Array.get(o, i); if (value != null) { if (excludeList.contains(value)) { buffer.append("circular reference"); } else if (value.getClass().isPrimitive() || value.getClass() == java.lang.Long.class || value.getClass() == java.lang.String.class || value.getClass() == java.lang.Integer.class || value.getClass() == java.lang.Boolean.class) { buffer.append(value); } else { buffer.append(dumpFields(value, callCount, excludeList)); } } } buffer.append(tabs.toString()); buffer.append("]\n"); } else { buffer.append("\n"); buffer.append(tabs.toString()); buffer.append("{\n"); while (oClass != null) { Field[] fields = oClass.getDeclaredFields(); for (int i = 0; i < fields.length; i++) { if (fields[i] == null) continue; buffer.append(tabs.toString()); fields[i].setAccessible(true); buffer.append(fields[i].getName()); buffer.append("="); try { Object value = fields[i].get(o); if (value != null) { if (excludeList.contains(value)) { buffer.append("circular reference"); } else if ((value.getClass().isPrimitive()) || (value.getClass() == java.lang.Long.class) || (value.getClass() == java.lang.String.class) || (value.getClass() == java.lang.Integer.class) || (value.getClass() == java.lang.Boolean.class)) { buffer.append(value); } else { buffer.append(dumpFields(value, callCount, excludeList)); } } } catch (IllegalAccessException e) { System.out.println("IllegalAccessException: " + e.getMessage()); } buffer.append("\n"); } oClass = oClass.getSuperclass(); } buffer.append(tabs.toString()); buffer.append("}\n"); } return buffer.toString(); } The method is initially called like this: System.out.println(dumpFields(obj, 0, null); So, basically I added an excludeList which contains all the previousely checked objects. Now, if an object contains another object and that object links back to the original object, it should not follow that object further down the chain. However, my logic seems to have a flaw as I still get stuck in an infinite loop. Does anyone know why this is happening?

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  • Problems with Asynchronous UDP Sockets

    - by ihatenetworkcoding
    Hi, I'm struggling a bit with socket programming (something I'm not at all familiar with) and I can't find anything which helps from google or MSDN (awful). Apologies for the length of this. Basically I have an existing service which recieves and responds to requests over UDP. I can't change this at all. I also have a client within my webapp which dispatches and listens for responses to that service. The existing client I've been given is a singleton which creates a socket and an array of response slots, and then creates a background thread with an infinite looping method that makes "sock.Receive()" calls and pushes the data received into the slot array. All kinds of things about this seem wrong to me and the infinite thread breaks my unit testing so I'm trying to replace this service with one which makes it's it's send/receives asynchronously instead. Point 1: Is this the right approach? I want a non-blocking, scalable, thread-safe service. My first attempt is roughly like this, which sort of worked but the data I got back was always shorter than expected (i.e. the buffer did not have the number of bytes requested) and seemed to throw exceptions when processed. private Socket MyPreConfiguredSocket; public object Query() { //build a request this.MyPreConfiguredSocket.SendTo(MYREQUEST, packet.Length, SocketFlags.Multicast, this._target); IAsyncResult h = this._sock.BeginReceiveFrom(response, 0, BUFFER_SIZE, SocketFlags.None, ref this._target, new AsyncCallback(ARecieve), this._sock); if (!h.AsyncWaitHandle.WaitOne(TIMEOUT)) { throw new Exception("Timed out"); } //process response data (always shortened) } private void ARecieve (IAsyncResult result) { int bytesreceived = (result as Socket).EndReceiveFrom(result, ref this._target); } My second attempt was based on more google trawling and this recursive pattern I frequently saw, but this version always times out! It never gets to ARecieve. public object Query() { //build a request this.MyPreConfiguredSocket.SendTo(MYREQUEST, packet.Length, SocketFlags.Multicast, this._target); State s = new State(this.MyPreConfiguredSocket); this.MyPreConfiguredSocket.BeginReceiveFrom(s.Buffer, 0, BUFFER_SIZE, SocketFlags.None, ref this._target, new AsyncCallback(ARecieve), s); if (!s.Flag.WaitOne(10000)) { throw new Exception("Timed out"); } //always thrown //process response data } private void ARecieve (IAsyncResult result) { //never gets here! State s = (result as State); int bytesreceived = s.Sock.EndReceiveFrom(result, ref this._target); if (bytesreceived > 0) { s.Received += bytesreceived; this._sock.BeginReceiveFrom(s.Buffer, s.Received, BUFFER_SIZE, SocketFlags.None, ref this._target, new AsyncCallback(ARecieve), s); } else { s.Flag.Set(); } } private class State { public State(Socket sock) { this._sock = sock; this._buffer = new byte[BUFFER_SIZE]; this._buffer.Initialize(); } public Socket Sock; public byte[] Buffer; public ManualResetEvent Flag = new ManualResetEvent(false); public int Received = 0; } Point 2: So clearly I'm getting something quite wrong. Point 3: I'm not sure if I'm going about this right. How does the data coming from the remote service even get to the right listening thread? Do I need to create a socket per request? Out of my comfort zone here. Need help.

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  • math.Random isn't working right

    - by RandomlyKnighted
    I'm trying to simulate a coin flip using the code below. public class Coin { public static double result; int[] count = new count[2]; public static void flip() { result = Math.random(); } public static boolean isHeads() { if (result == 0.0) { count[0]++; return false; } else { count[1]++; return true; } } public static void main(String[] args) { flip(); isHeads(); System.out.println(count[0]); System.out.println(count[1]); } } For some reason Eclipse says that the import java.util.Random; is never used even though I'm clearly using it. I didn't put my for loop into the code above but it loops n number of times and then outputs the result. No matter how many times it loops it always returns that the result is greater than 0.0 which can't be right. Am I calling Math.random incorrectly?

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  • Image on mouseover takes space on PageLoad.

    - by Ram
    Hello, I am trying to show an image on Mouseover and hide it on Mouseout. I am successful in mouseover and mouseout but the image is actually taking the space around the text though i have visibility as hidden.. The text is surrounded with the space of image but the image is displayed on mouseover. Here is the code: <td valign="middle" class="table_td td top" style="width: 347px"> <div id="Style16" style="position:relative; height:100%; left:50%; bottom:700%; visibility:hidden; border:solid 0px #CCC; padding:5px"><img src="images/window-decal-image.gif"></div> <span class="feature_text" style="cursor:pointer" onmouseover="ShowPicture('Style16',1)" onmouseout="ShowPicture('Style16',0)" id="a16">Storefront Window Decal</span> <span class="feature_text_small">(5"x3.5" double sided decal)</span></td> <script language="javascript" type="text/javascript"> function ShowPicture(id,Source) { var vis, elem; if (1 == Source) { vis = "visible"; } else if (0 == Source) { vis = "hidden"; } else { throw new RangeError("Unknown Flag"); } if (elem = document.getElementById(id)) { elem.style.visibility = vis; } else { throw new TypeError("Element with id '"+id+"' does not exist."); } return vis; } </script>

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