Search Results

Search found 3211 results on 129 pages for 'mpi beginner'.

Page 50/129 | < Previous Page | 46 47 48 49 50 51 52 53 54 55 56 57  | Next Page >

• Why won't the following haskell code compile?

  - by voxcogitatio

  I'm in the process of writing a small lisp interpreter in haskell. In the process i defined this datatype, to get a less typed number; data Number = _Int Integer | _Rational Rational | _Float Double deriving(Eq,Show) Compiling this fails with the following error: ERROR "types.hs":16 - Syntax error in data type declaration (unexpected `|') Line 16 is the line w. the first '|' in the code above.

  Read the article

• In DOM is it OK to use .notation for getting/setting attributes?

  - by Ziggy

  Hi In DOM, is it OK to refer to an element's attributes like this: var universe = document.getElementById('universe'); universe.origin = 'big_bang'; universe.creator = null; universe.style.deterministic = true; ? My deep respect for objects and their privacy, and my sense that things might go terribly wrong if I am not careful, makes me want to do everything more like this: var universe = document.getElementById('universe'); if(universe.hasAttribute('origin')) then universe.origin = 'big_bang'; etc... Is it really necessary to use those accessor methods? Of course it may be more or less necessary depending on how certain I am that the elements I am manipulating will have the attributes I expect them to, but in general do the DOM guys consider it OK to use .notation rather than getters and setters? Thanks!

  Read the article

• C++: Cannot convert from foo& to foo*

  - by Rosarch

  I have a method: odp(foo& bar); I'm trying to call it: foo baz; odp(&baz); I get a compiler error: error C2664: "odp" cannot convert parameter 1 from 'foo *' to 'foo &' What am I doing wrong? Aren't I passing in a reference to baz? UPDATE: Perhaps I have a misconception about the relationship between pointers and references. I thought that they were the same, except references couldn't be null. Is that incorrect?

  Read the article

• Java cannot find symbol enum

  - by JDelage

  Hi, I'm modeling a chess game on Java, and I'm having some problem. Here's what the code looks like (the relevant parts): Enum class Couleur.java: public enum Couleur {BLANC, NOIR} Piece.java: public abstract class Piece { (...) public Piece(Couleur couleurParam){ this.couleurPiece = couleurParam; } (...) } And finally Tour.java: public class Tour extends Piece { (...) public Tour(Couleur couleurParam){ super(couleurParam); } (...) } All the .java files are in the same folder. Yet at compile I get a "cannot find symbol symbol : variable NOIR location: class Plateau" (Plateau is the class that instantiates Tour.) Can anyone help me figure out what's wrong here? Many thanks, JDelage

  Read the article

• Question about Radio button/PHP/MySQL

  - by Marcelo

  Hi, I'm an engineering student and I'm developing a simple software based on HTML, PHP and mysql. I learned this topics on w3schools. I know only the basics. I tried to search about this in this website but I found questions about PHP, MySQL and HTML radio buttons which were much more complex than I need and that I could understand. Sorry for the English. (Q1) Ex: $email=$_REQUEST['email'] , in this case the input is text, if it where like a radio button for ex: sex: male or female, how would it be? (Q2) what would be the type of this field (for exemple sex in question 1) in the database: text, int, varchar ? Thanks for the attention

  Read the article

• What is a really simple explanation of unit testing?

  - by ensnare

  I've never done any unit testing before, and would like to learn what it is and how it can be useful in my Python code. I've read through a few Python unit testing tutorials online but they're all so complicated and assume an extended programming background. I'm using Python with Pylons to create a simple web app. Any simple examples would be greatly appreciated. Thanks!

  Read the article

• Unexpected behaviour of Order by clause

  - by Newbie

  I have a table which looks like Col1 col2 col3 col4 col5 1 5 1 4 6 1 4 0 3 7 0 1 5 6 3 1 8 2 1 5 4 3 2 1 4 The script is declare @t table(col1 int, col2 int, col3 int,col4 int,col5 int) insert into @t select 1,5,1,4,6 union all select 1,4,0,3,7 union all select 0,1,5,6,3 union all select 1,8,2,1,5 union all select 4,3,2,1,4 If I do a sorting (ascending), the output is Col1 col2 col3 col4 col5 0 1 5 6 3 1 4 0 3 7 1 5 1 4 6 1 8 2 1 5 4 3 2 1 4 The query is Select * from @t order by col1,col2,col3,col4,col5 But as can be seen that the sorting output is wrong (col2 to col5). I want the output to be every column being sorted in ascending order i.e. Col1 col2 col3 col4 col5 0 1 0 1 3 1 3 1 1 4 1 4 2 3 5 1 5 2 4 6 4 8 5 6 7 Why so and how to overcome this? Thanks in advance

  Read the article

• vector related memory allocation question

  - by memC

  hi all, I am encountering the following bug. I have a class Foo . Instances of this class are stored in a std::vector vec of class B. in class Foo, I am creating an instance of class A by allocating memory using new and deleting that object in ~Foo(). the code compiles, but I get a crash at the runtime. If I disable delete my_a from desstructor of class Foo. The code runs fine (but there is going to be a memory leak). Could someone please explain what is going wrong here and suggest a fix? thank you! class A{ public: A(int val); ~A(){}; int val_a; }; A::A(int val){ val_a = val; }; class Foo { public: Foo(); ~Foo(); void createA(); A* my_a; }; Foo::Foo(){ createA(); }; void Foo::createA(){ my_a = new A(20); }; Foo::~Foo(){ delete my_a; }; class B { public: vector<Foo> vec; void createFoo(); B(){}; ~B(){}; }; void B::createFoo(){ vec.push_back(Foo()); }; int main(){ B b; int i =0; for (i = 0; i < 5; i ++){ std::cout<<"\n creating Foo"; b.createFoo(); std::cout<<"\n Foo created"; } std::cout<<"\nDone with Foo creation"; std::cout << "\nPress RETURN to continue..."; std::cin.get(); return 0; }

  Read the article

• Creating a unique id for a Core Data program on the iPhone

  - by Big Twisty

  I am fairly new at programming in Objective-C, having been a windows programmer since I was a kid. I am falling in LOVE with it. I am, however, having a bit of trouble figuring out this Core Data stuff. How do I create a new entry with a unique ID? In SQL I would just declare one field as an autoincrement field. I'm not seeing anything like that here, but I could just be missing something. I just want an auto incrementing NSInteger field, so when I manually add items to the database, I will have some form of reference to them.

  Read the article

• convert string to dict using list comprehension in python

  - by Pavel

  I have came across this problem a few times and can't seem to figure out a simple solution. Say I have a string string = "a=0 b=1 c=3" I want to convert that into a dictionary with a, b and c being the key and 0, 1, and 3 being their respective values (converted to int). Obviously I can do this: list = string.split() dic = {} for entry in list: key, val = entry.split('=') dic[key] = int(val) But I don't really like that for loop, It seems so simple that you should be able to convert it to some sort of list comprehension expression. And that works for slightly simpler cases where the val can be a string. dic = dict([entry.split('=') for entry in list]) However, I need to convert val to an int on the fly and doing something like this is syntactically incorrect. dic = dict([[entry[0], int(entry[1])] for entry.split('=') in list]) So my question is: is there a way to eliminate the for loop using list comprehension? If not, is there some built in python method that will do that for me?

  Read the article

• Should I invest time in learning Java language these days? (question from a greenhorn)

  - by dave-keiture

  Hi experts, Assuming you've already had a chance to look through the lambda syntax proposed for Java7 (and the other things that have happened with Java, after Oracle has bought Sun + obvious problems in Java Community Process), what do you think is the future of Java language? Should I, as a Java greenhorn, invest time in learning Java language (not talking about the core JVM, which definitely will survive anything, and worth investments), or concentrate on Scala, Groovy, or other hybrid languages on the JVM platform (I've came into Java world from PHP/Ruby). Thanks in advance.

  Read the article

• A Beginners' Guide to Learning JavaScript?

  - by CloseDiamond

  There's a few mentions of Javascript newbies getting starting by checking out some of Douglas Crockford's work (http://stackoverflow.com/questions/11246/best-resources-to-learn-javascript), but none of his resources seem to be for those looking to learn from the ground up. Are there any suggestions for complete beginners regarding how best to learn JavaScript? Personally I have plenty of HTML and CSS experience, and some PHP (which would help learning JS), but for those that don't know any programming language what would you recommend?

  Read the article

• How does one FTP a directory with multiple sub-directories?

  - by CheesePls

  I need to ftp a directory over to another system and I don't want to have to recreate all the folders on the other system by hand. How would I do this? P.S. I am aware there is a similar question here but none of the answers work and did not want to revive the dead post EDIT: I can't install anything

  Read the article

• [Python] OR in regular expression?

  - by www.yegorov-p.ru

  Hello. I have text file with several thousands lines. I want to parse this file into database and decided to write a regexp. Here's part of file: blablabla checked=12 unchecked=1 blablabla unchecked=13 blablabla checked=14 As a result, I would like to get something like (12,1) (0,13) (14,0) Is it possible?

  Read the article

• Which LOGO implementation?

  - by Lukasz Lew

  I want to show my young cousin (12) programming. I think that LOGO is a good start. Which implementation should I use? (windows)

  Read the article

• database connection OK,result not appear

  - by klox

  hi..all.for now i'm already connected to database but the result not appear at Tuner range is"+res+"this is my code: var str=data[0]; var matches=str.match(/[EE|EJU].*D/i); $.ajax({ type:"post", url:"process1.php", data:"tversion="+matches+"&action=tunermatches", cache:false, async:false, success: function(res){ $('#value').replacewith("<div id='value'><h6>Tuner range is"+res+".</h6></div>"); } }); }); and this is my process file: //connect to database $dbc=mysql_connect(_SRV,_ACCID,_PWD) or die(_ERROR15.": ".mysql_error()); $db=mysql_select_db("qdbase",$dbc) or die(_ERROR17.": ".mysql_error()); switch(postVar('action')) { case 'tunermatches' : tunermatches(postVar('tversion')); break; function tunermatches($tversion)){ $Tuner=mysql_real_escape_string($tversion); $sql= "SELECT remark FROM settingdata WHERE itemname='Tuner_range' AND itemdata='".$Tunermatches."'"; $res=mysql_query($sql) or die (_ERROR26.":".mysql_error()); $dat=mysql_fetch_array($res,MYSQL_NUM); if($dat[0]>0) { echo $dat[0]; } mysql_close($dbc); }

  Read the article

• I'm having a problem identifying a floating point exception.

  - by Peter Stewart

  I'm using c++ in visual studio express to generate random expression trees for use in a genetic algorithm type of program. Because they are random, the trees often generate (I'll call them exceptions, I'm not sure what they are) Thanks to a suggestion by George, I turned the mask _MCW_EM on so that hardware interrupts are turned off. (the default) So, the program runs uninterrupted, but some of the values returned are: -1.#INF, -1.#NAN, -1.#INV. I don't know how to identify these so that I can throw an exeption: if ( variable == -1.#INF) ?? DigitalRoss in this post seemed to have the solution, but as I understood it I couldn't make it work. I've been looking all over the place for this simple bit of code, that I assumed would be used all the time, but have had no luck. thanks

  Read the article

• Interacting With Class Objects in Ruby

  - by michaelmichael

  How can I interact with objects I've created based on their given attributes in Ruby? To give some context, I'm parsing a text file that might have several hundred entries like the following: ASIN: B00137RNIQ -------------------------Status Info------------------------- Upload created: 2010-04-09 09:33:45 Upload state: Imported Upload state id: 3 I can parse the above with regular expressions and use the data to create new objects in a "Product" class: class Product attr_reader :asin, :creation_date, :upload_state, :upload_state_id def initialize(asin, creation_date, upload_state, upload_state_id) @asin = asin @creation_date = creation_date @upload_state = upload_state @upload_state_id = upload_state_id end end After parsing, the raw text from above will be stored in an object that look like this: [#<Product:0x00000101006ef8 @asin="B00137RNIQ", @creation_date="2010-04-09 09:33:45 ", @upload_state="Imported ", @upload_state_id="3">] How can I then interact with the newly created class objects? For example, how might I pull all the creation dates for objects with an upload_state_id of 3? I get the feeling I'm going to have to write class methods, but I'm a bit stuck on where to start.

  Read the article

• can I have multiline text with GD and PHP?

  - by alekone

  hello! I'm trying to output multiline text with GD+PHP but can't get it working. my php knowledge is really basic. here's the code, any idea on how to output 2 or 3 lines of text? $theText = (isset($_GET['caption']))? stripslashes($_GET['caption']) :''; imagettftext($baseImage, $textSize, $textAngle, $textXposition, $textYposition, $textColor, $fontName, $theText);

  Read the article

• Python unhash value

  - by blah01

  Hi all I am a newbie to the python. Can I unhash, or rather how can I unhash a value. I am using std hash() function. What I would like to do is to first hash a value send it somewhere and then unhash it as such: #process X hashedVal = hash(someVal) #send n receive in process Y someVal = unhash(hashedVal) #for example print it print someVal Thx in advance

  Read the article

• how to start learning Java scripting

  - by antriksh

  Dear All, I am experienced in the technical support like Linux, oracle, sunos etc and but if i say scripting i know little bit of bash. Now i promoted to manage technical engineers inuding some java script developers, so i want to learn java scripting so that i can understand engineers. Hope you understand. Can you please advise me how can i start java scripting and point me to some simple docs and examples.

  Read the article

• "Finding" an object instance of a known class?

  - by Sean C

  My first post here (anywhere for that matter!), re. Cocoa/Obj-C (I'm NOT up to speed on either, please be patient!). I hope I haven't missed the answer already, I did try to find it. I'm an old-school procedural dog (haven't done any programming since the mid 80's, so I probably just can't even learn new tricks), but OOP has my head spinning! My question is: is there any means at all to "discover/find/identify" an instance of an object of a known class, given that some OTHER unknown process instantiated it? eg. somthing that would accomplish this scenario: (id) anObj = [someTarget getMostRecentInstanceOf:[aKnownClass class]]; for that matter, "getAnyInstance" or "getAllInstances" might do the trick too. Background: I'm trying to write a plugin for a commercial application, so much of the heavy lifting is being done by the app, behind the scenes. I have the SDK & header files, I know what class the object is, and what method I need to call (it has only instance methods), I just can't identify the object for targetting. I've spent untold hours and days going over Apples documentation, tutorials and lots of example/sample code on the web (including here at Stack Overflow), and come up empty. Seems that everything requires a known target object to work, and I just don't have one. Since I may not be expressing my problem as clearly as needed, I've put up a web page, with diagram & working sample pages to illustrate: http://www.nulltime.com/svtest/index.html Any help or guidance will be appreciated! Thanks.

  Read the article

• jQuery: Stopping a periodic ajax call?

  - by Legend

  I am writing a small jQuery plugin to update a set of Divs with content obtained using Ajax calls. Initially, let's assume we have 4 divs. I am doing something like this: (function($) { .... .... //main function $.fn.jDIV = { init: function() { ... ... for(var i = 0; i < numDivs; i++) { this.query(i); } this.handlers(); }, query: function(divNum) { //Makes the relevant ajax call }, handlers: function() { for(var i = 0; i < numDivs; i++) { setInterval("$.fn.jDIV.query(" + i + ")", 5000); } } }; })(jQuery); I would like to be able to enable and disable a particular ajax query. I was thinking of adding a "start" and "stop" instead of the "handlers" function and subsequently storing the setInterval handler like this: start: function(divNum) { divs[divNum] = setInterval("$.fn.jDIV.query(" + i + ")", 5000); }, stop: function(divNum) { clearInterval(divs[divNum]); } I did not use jQuery to setup and destroy the event handlers. Is there a better approach (perhaps using more of jQuery) to achieve this?

  Read the article

• Does everything after my try statement have to be encompassed in that try statement to access variab

  - by Mithrax

  I'm learning java and one thing I've found that I don't like, is generally when I have code like this: import java.util.*; import java.io.*; public class GraphProblem { public static void main(String[] args) { if (args.length < 2) { System.out.println("Error: Please specify a graph file!"); return; } FileReader in = new FileReader(args[1]); Scanner input = new Scanner(in); int size = input.nextInt(); WeightedGraph graph = new WeightedGraph(size); for(int i = 0; i < size; i++) { graph.setLabel(i,Character.toString((char)('A' + i))); } for(int i = 0; i < size; i++) { for(int j = 0; j < size; j++) { graph.addEdge(i, j, input.nextInt()); } } // .. lots more code } } I have an uncaught exception around my FileReader. So, I have to wrap it in a try-catch to catch that specific exception. My question is does that try { } have to encompass everything after that in my method that wants to use either my FileReader (in) or my Scanner (input)? If I don't wrap the whole remainder of the program in that try statement, then anything outside of it can't access the in/input because it may of not been initialized or has been initialized outside of its scope. So I can't isolate the try-catch to just say the portion that intializes the FileReader and close the try statement immediately after that. So, is it the "best practice" to have the try statement wrapping all portions of the code that are going to access variables initialized in it? Thanks!

  Read the article

• How do I use "this" in a member function?

  - by Peter Stewart

  I've written a member function of class Node to read a tree of Nodes in postfix order. It will be called by the Node instance which is the root node of the tree. So: N.postfix(); these appear to be illeagal: *this->left.postfix(); *this->right.postfix(); What is the proper way to do this? class Node { public: const char *cargo; int depth; Node *left; Node *right void Node::postfix() { if (this==__nullptr) { return; } else { *this->left.postfix(); *this->right.postfix(); out<<*this->cargo<<"\n"; return; } };

  Read the article

< Previous Page | 46 47 48 49 50 51 52 53 54 55 56 57  | Next Page >