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  • NSMutableDictionary of NSMutableSets... sorting this out

    - by Mike
    I have a NSMutableDictionary of NSMutableSets. Each set entry is a string, something like this: NSMutableSet *mySet = [NSMutableSet setWithObjects: [NSString stringWithFormat:@"%d", time1], [NSString stringWithFormat:@"%d", time2], [NSString stringWithFormat:@"%d", time3], nil]; // time 1,2,3, are NSTimeInterval variables then I store each set on the dictionary using this: NSString *rightNowString = [NSString stringWithFormat:@"%d", rightNow]; [myDict setValue:mySet forKey:rightNow]; // rightNow is NSTimeInterval as rightNow key can occur out of order, I end with a NSDictionary that is not ordered by rightNow. How can I sort this NSDictionary by its keys considering that they are numbers stored as strings on the dictionary...? I don't care for ordering the sets, just the dictionary. thanks for any help.

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  • Which is faster in Python: x**.5 or math.sqrt(x)?

    - by Casey
    I've been wondering this for some time. As the title say, which is faster, the actual function or simply raising to the half power? UPDATE This is not a matter of premature optimization. This is simply a question of how the underlying code actually works. What is the theory of how Python code works? I sent Guido van Rossum an email cause I really wanted to know the differences in these methods. My email: There are at least 3 ways to do a square root in Python: math.sqrt, the '**' operator and pow(x,.5). I'm just curious as to the differences in the implementation of each of these. When it comes to efficiency which is better? His response: pow and ** are equivalent; math.sqrt doesn't work for complex numbers, and links to the C sqrt() function. As to which one is faster, I have no idea...

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  • How to use variables with regex?

    - by dontoo
    This is the input string: 23x^45*y or 2x^2 or y^4*x^3. I am matching ^[0-9]+ after letter x. In other words I am matching x followed by ^ followed by numbers. Problem is that I don't know that I am matching x, it could be any letter that I stored as variable in my char array. For example: foreach (char cEle in myarray) // cEle is letter in char array x, y, z, ... { match CEle in regex(input) //PSEUDOCODE } I am new to regex and I new that this can be done if I define regex variables, but I don't know how.

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  • Predict Stock Market Values

    - by mrlinx
    I'm building a web semantic project that gathers the maximum ammount of historic data about a certain company and tries to predict its future market stock values. For data I have the historic stock values (not normalized), news (0 to 1 polarity) and subjective content (also a 0 to 1 polarity). What is the best AI system to train and use for this kind of objective? Is a simple NN with back-propagation training the best I can hope for? update: Everyone is concerned about the quality of this system. Although I'm pretty sure the system is as good as a random prediction (or even worse), this is a school project around artificial intelligence and web semantics. Therefore I'm only concerned in picking the best kind of train method for the data I have (NN, RBF, SVM, Bayes, neuro-fuzzy, etc). Its not about making money.

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  • Is it possible to shorten my main function in this code?

    - by AjiPorter
    Is it possible for me to shorten my main() by creating a class? If so, what part of my code would most likely be inside the class? Thanks again to those who'll answer. :) #include <iostream> #include <fstream> #include <string> #include <ctime> #include <cstdlib> #define SIZE 20 using namespace std; struct textFile { string word; struct textFile *next; }; textFile *head, *body, *tail, *temp; int main() { ifstream wordFile("WORDS.txt", ios::in); // file object constructor /* stores words in the file into an array */ string words[SIZE]; char pointer; int i; for(i = 0; i < SIZE; i++) { while(wordFile >> pointer) { if(!isalpha(pointer)) { pointer++; break; } words[i] = words[i] + pointer; } } /* stores the words in the array to a randomized linked list */ srand(time(NULL)); int index[SIZE] = {0}; // temporary array of index that will contain randomized indexes of array words int j = 0, ctr; // assigns indexes to array index while(j < SIZE) { i = rand() % SIZE; ctr = 0; for(int k = 0; k < SIZE; k++) { if(!i) break; else if(i == index[k]) { // checks if the random number has previously been stored as index ctr = 1; break; } } if(!ctr) { index[j] = i; // assigns the random number to the current index of array index j++; } } /* makes sure that there are no double zeros on the array */ ctr = 0; for(i = 0; i < SIZE; i++) { if(!index[i]) ctr++; } if(ctr > 1) { int temp[ctr-1]; for(j = 0; j < ctr-1; j++) { for(i = 0; i < SIZE; i++) { if(!index[i]) { int ctr2 = 0; for(int k = 0; k < ctr-1; k++) { if(i == temp[k]) ctr2 = 1; } if(!ctr2) temp[j] = i; } } } j = ctr - 1; while(j > 0) { i = rand() % SIZE; ctr = 0; for(int k = 0; k < SIZE; k++) { if(!i || i == index[k]) { ctr = 1; break; } } if(!ctr) { index[temp[j-1]] = i; j--; } } } head = tail = body = temp = NULL; for(j = 0; j < SIZE; j++) { body = (textFile*) malloc (sizeof(textFile)); body->word = words[index[j]]; if(head == NULL) { head = tail = body; } else { tail->next = body; tail = body; cout << tail->word << endl; } } temp = head; while(temp != NULL) { cout << temp->word << endl; temp = temp->next; } return 0; }

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  • PHP Array to String equivalent

    - by Matt
    Hey all, I'm wondering if anyone has a recursive solution to converting an array to a string. Here's what I mean: An array $args that has the following contents: Array ( [0] => $hello [1] => 411px [Jeeves] => Array ( [compiling] => 1 ) ) Result after calling arr_to_string($args): array($hello,"411px", "Jeeves" => array("compiling" => 1)); Note: It recognizes the $ sign in front and therefore does not add quotes. It does the same for numbers. Anyone have any solution or can point me in the right direction? Thanks! Matt Mueller

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  • Add a custom compiler to XCode 3.2

    - by racha
    I have a working gcc 4.3.3 toolchain for an ARM Cortex-m3 and would like to integrate it into XCode. Is there a way to set up XCode (3.2) to use this gcc toolchain instead of the built-in GCC 4.2? What I've tried so far: I've added a modified copy of the GCC 4.2.xcplugin and changed the name, version and executable path. It shows up in XCode but whenever I set the "C/C++ Compiler Version" to the custom compiler it fails with Invalid value '4.3.3' for GCC_VERSION It seems like the valid version numbers are hardcoded somewhere else because even when I remove the original GCC 4.2.xcplugin, the value 4.2 remains valid (but is not visible in the "C/C++ Compiler Version" drop down anymore).

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  • Flash CS5 and dynamic textfields

    - by hood
    I have a "shell" that started life in Flash CS3 (Flash 9, AS3) that has been since used with CS4 and now CS5. It creates TextFields in ActionScript for display (reading the content of those fields from XML). The text fields are either Myriad Pro Regular or Myriad Pro Semibold, both are embedded in the SWF from the Library (any given text field will only use one of those fonts) and using Advanced anti-aliasing. Once a FLA goes into CS5 is still has the same problem when saved back into CS4. The problem is the spacing between letters are now quite random, and the width of each text field is too wide (by about 10%). Changing the letterSpacing property (to something negative) makes this more noticeable. I read on here about Font.registerFont(MyriadPro) but that doesn't seem to be doing anything. Does anyone know how to make CS5 behave like previous versions of Flash? I'm using Flash Professional on Snow Leopard (as part of CS5 Web Premium).

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  • Regex and PHP for extracting contents between tags with several line breaks

    - by John
    How can I extract the content between tags with several line breaks? I'm a newbie to regex, who would like to know how to handle unknown numbers of line break to match my query. Task: Extract content between <div class="test"> and the first closing </div> tag. Original source: <div class="test">optional text<br/> content<br/> <br/> content<br/> ... content<br/><a href="/url/">Hyperlink</a></div></div></div> I've worked out the below regex, /<div class=\"test\">(.*?)<br\/>(.*?)<\/div>/ Just wonder how to match several line breaks using regex. There is DOM for us but I am not familiar with that.

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  • Creating DescriptionAttribute on Enumeration Field using System.Reflection.Emit

    - by Manish Sinha
    I have a list of strings which are candidates for Enumerations values. They are Don't send diffs 500 lines 1000 lines 5000 lines Send entire diff The problem is that spaces, special characters are not a part of identifiers and even cannot start with a number, so I would be sanitizing these values to only chars, numbers and _ To keep the original values I thought of putting these strings in the DescriptionAttribute, such that the final Enum should look like public enum DiffBehvaiour { [Description("Don't send diffs")] Dont_send_diffs, [Description("500 lines")] Diff_500_lines, [Description("1000 lines")] Diff_1000_lines, [Description("5000 lines")] Diff_5000_lines, [Description("Send entire diff")] Send_entire_diff } Then later using code I will retrieve the real string associated with the enumeration value, so that the correct string can be sent back the web service to get the correct resource. I want to know how to create the DescriptionAttribute using System.Reflection.Emit Basically the question is where and how to store the original string so that when the Enumeration value is chosen, the corresponding value can be retrieved. I am also interested in knowing how to access DescriptionAttribute when needed.

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  • An interview question.

    - by SysAdmin
    I recently came across a question somewhere Suppose you have an array of 1001 integers. The integers are in random order, but you know each of the integers is between 1 and 1000 (inclusive). In addition, each number appears only once in the array, except for one number, which occurs twice. Assume that you can access each element of the array only once. Describe an algorithm to find the repeated number. If you used auxiliary storage in your algorithm, can you find an algorithm that does not require it? what i am interested to know is the second part. i.e without using auxiliary storage . do you have any idea?

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  • jquery .live() event interactions

    - by ddango
    Let's say I have a scenario where I have a global plugin (or at least a plugin that binds to a wider array of events). This plugin takes a selector, and binds a live click to it. Something in pseudo-jquery that might look like this: $.fn.changeSomething = function(){ $(this).live("change", function(){ alert("yo");}); } On another page, I have an additional live binding something like this: $("input[type='checkbox']").live("click", function(){alert("ho");}); Within this scenario, the checkbox would ideally end up being bound to both live events. What I'm seeing is that the change event fires as it should, and I'm alerted "yo". However, using this live click event, I never trigger it. However, using an explicit click binding, I DO hit it. The easy workaround is to trigger a click event at the end of the live change handler, but this seems janky to me. Any ideas? Note that this is using jquery 1.4.2 and only occurs in IE8 (I supposed 6/7 would too, but I haven't tested them).

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  • How can I pop a view from a UINavigationController and replace it with another in one operation?

    - by Matt Brandt
    I have an application where I need to remove one view from the stack of a UINavigationController and replace it with another. The situation is that the first view creates an editable item and then replaces itself with an editor for the item. When I do the obvious solution within the first view: MyEditViewController *mevc = [[MYEditViewController alloc] initWithGizmo: gizmo]; [self retain]; [self.navigationController popViewControllerAnimated: NO]; [self.navigationController pushViewController: mevc animated: YES]; [self release]; I get very strange behavior. Usually the editor view will appear, but if I try to use the back button on the nav bar I get extra screens, some blank, and some just screwed up. The title becomes random too. It is like the nav stack is completely hosed. What would be a better approach to this problem? Thanks, Matt

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  • Render label for a field inside ASP.NET MVC 2 editor templates

    - by artvolk
    I'm starting to use DataAnnotations in ASP.NET MVC and strongly typed template helpers. Now I have this in my views (Snippet is my custom type, Created is DateTime): <tr> <td><%= Html.LabelFor(f => Model.Snippet.Created) %>:</td> <td><%= Html.EditorFor(f => Model.Snippet.Created)%></td> </tr> The editor template for DateTime is like this: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<System.DateTime>" %> <%=Html.TextBox("", Model.ToString("g"))%> But now I want to put inside editor template the whole <tr>, so I'd like to have just this in my view: <%= Html.EditorFor(f => Model.Snippet.Created)%> And something like this in editor template, but I don't know how to render for for label attribute, it should be Snippet_Created for my example, the same as id\name for textbox, so pseudo code: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<System.DateTime>" %> <tr> <td><label for="<What to place here???>"><%=ViewData.ModelMetadata.DisplayName %></label></td> <td><%=Html.TextBox("", Model.ToString("g"))%></td> </tr> The Html.TextBox() have the first parameter empty and id\name for textbox is generated corectly. Thanks in advance!

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  • Junit vs TestNG

    - by Sam Merrell
    At work we are currently still using Junit3 to run our tests. We have been considering switching over to Junit4 for new tests being written but I have been keeping an eye on TestNG for a while now. What experiences have you all had with either Junit4 or TestNG and which seems to work better for very large numbers of tests. Having flexibility in writing tests is also important to us since our functional tests cover a wide aspect and need to be written in a variety of ways to get results. Old tests will not be re-written as they do their job just fine. What I would like to see in new tests though is flexibility in the way the test can be written, natural assertions, grouping, and easily distributed test executions.

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  • Throw of a die in Java

    - by Arkapravo
    The throw of a die is a popular program in Java, public class Die { /* This program simulates rolling a die */ public static void main(String[] args) { int die; // The number on the die. die = (int)(Math.random()*6 + 1); System.out.println (die); } // end main() } // end class What I wish to do is make it repeat, 500 times. I have not been able to put this program into a loop of 500. I usually program in Python, thus I guess my Java has rusted ! Any help is most welcome !

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  • Floating point arithmetic is too reliable.

    - by mcoolbeth
    I understand that floating point arithmetic as performed in modern computer systems is not always consistent with real arithmetic. I am trying to contrive a small C# program to demonstrate this. eg: static void Main(string[] args) { double x = 0, y = 0; x += 20013.8; x += 20012.7; y += 10016.4; y += 30010.1; Console.WriteLine("Result: "+ x + " " + y + " " + (x==y)); Console.Write("Press any key to continue . . . "); Console.ReadKey(true); } However, in this case, x and y are equal in the end. Is it possible for me to demonstrate the inconsistency of floating point arithmetic using a program of similar complexity, and without using any really crazy numbers? I would like, if possible, to avoid mathematically correct values that go more than a few places beyond the decimal point.

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  • Graph databases and Php

    - by stagas
    I want to use a graph database using php. Can you point out some resources on where to get started? Is there any example code / tutorial out there? Or are there any other methods of storing data that relate to each other in totally random/abstract situations? Very abstract example of the relations needed: John relates to Mary, both relate to School, John is Tall, Mary is Short, John has Blue Eyes, Mary has Green Eyes, query I want is which people are related to 'Short people that have Green Eyes and go to School' - answer John It is possible in MySQL but it would require a fixed set of attributes/columns for each item and a complex non-flexible query, instead I need every attribute to be an item by itself and instead of 'belonging' to something, to be 'related' to something.

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  • Atlas style map index for static google map

    - by Ben Holland
    Hello, I'm using a static google map, but really this problem could apply to any maps project. I want to divide a map into multiple quadrants (of say 50x50 pixels) and label the columns as A, B, C.... and the rows as 1, 2, 3... Next I plan to do something like, 1) Find the markers which are the farthest north, east, south, and west 2) Use that info to to define the bounding boxes of each row and column box 3) Classify each marker by its row and column (Example Marker 1 = [A,2]) A few requirements, I don't know the zoom level because I let Google set the zoom level appropriately for me and I would rather not use an algorithm that is dependent on a zoom level. I do however know the locations of all of the markers that are shown on the map. Here is an example of a map that I would like to classify the markers for, static map example link. I found these which look like a good start, Resource 1, Resource 2 But I think I'm still in need of some help getting started. Can anyone help write out some pseudo code or post a few more resources? I'm kind of in a rut at the moment. Thanks! Much appreciated of any help!

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  • Laws of Computer Science and Programming

    - by Jonas
    We have Amdahl's law that basically states that if your program is 10% sequential you can get a maximum 10x performance boost by parallelizing your application. Another one is Wadler's law which states that In any language design, the total time spent discussing a feature in this list is proportional to two raised to the power of its position. 0. Semantics 1. Syntax 2. Lexical syntax 3. Lexical syntax of comments My question is this: What are the most important (or at least significant / funny but true / sad but true) laws of Computer Science and programming? I want named laws, and not random theorems, So an answer should look something like Surname's (law|theorem|conjecture|corollary...) Please state the law in your answer, and not only a link. Edit: The name of the law does not need to contain it's inventors surname. But I do want to know who stated (and perhaps proved) the law

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  • Racket: change dotted pair to list

    - by user2963128
    I have a program that recursively calls a hashtable and prints out data from it. Unfortunately my hashtable seems to be saving data as dotted pairs so when I call the hashtable I get an error saying that there is no data for it because its tryign to search the hashtable for a dotted pair instead of a list. Is there an easy way to make the dotted pair into a regular list? IE im getting '("was" . "beginning") instead of '("was" "beginning") Is there a way to change this without re-writing how my hashtable store stuff? im using the let function to set a variable to this and then calling another function based on this variable (let ((data ( list-ref(hash-ref Ngram-table key) (random (length (hash-ref Ngram-table key)))))) is there a way to make the value stored in data just a list like this '("var1" "var2") instead of a dotted pair? edit: im getting dotted pairs because im using let to set data to the part of the hashtable's key and one of the elements in that hash.

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  • PHP: Alternative to SESSIONS

    - by iamjonesy
    Hi, I have a PHP application that relies on session variables quite a lot. After login the user get redirected to a page that executes code to set up a load of session variables depending on who the user is. The application is using data from different sources and the sessions are used to store ID numbers to query the databases. So when the user goes to a page that will query their asset management system their ID for that particular database is called via the session. I've had a LOT of problems with session variables recently. Sometimes only one session file is created during the lifetime of the app, and sometimes each session request results in a new session id (still haven't managed to find out why!). My question is this. Is there an alternative to using session variables for this? Like globals or some other way? Any help most appreciated! Regards, Jonesy

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  • Why unsigned int contained negative number

    - by Daziplqa
    Hi All, I am new to C, What I know about unsigned numerics (unsigned short, int and longs), that It contains positive numbers only, but the following simple program successfully assigned a negative number to an unsigned int: 1 /* 2 * ===================================================================================== 3 * 4 * Filename: prog4.c 5 * 6 * ===================================================================================== 7 */ 8 9 #include <stdio.h> 10 11 int main(void){ 12 13 int v1 =0, v2=0; 14 unsigned int sum; 15 16 v1 = 10; 17 v2 = 20; 18 19 sum = v1 - v2; 20 21 printf("The subtraction of %i from %i is %i \n" , v1, v2, sum); 22 23 return 0; 24 } The output is : The subtraction of 10 from 20 is -10

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  • Add a thousands separator to a total with Javascript or jQuery?

    - by Matt
    I have a function that sums a column of data in an html table. It does so admirably only I would like to have it put the commas in there that are needed to separate the thousands. Initially, you'll note, there are commas in the numbers being added. So that the function will add them, they are removed. How do I add the commas back in there? <script type="text/javascript"> function sumOfColumns(tableID, columnIndex, hasHeader) { var tot = 0; $("#" + tableID + " tr" + (hasHeader ? ":gt(0)" : "")) .children("td:nth-child(" + columnIndex + ")") .each(function() { tot += parseInt($(this).html().replace(',', '')); }); return "Total Pounds Entered : " + tot; } </script>

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  • Graph Algorithm To Find All Paths Between N Arbitrary Vertices

    - by russtbarnacle
    I have an graph with the following attributes: Undirected Not weighted Each vertex has a minimum of 2 and maximum of 6 edges connected to it. Vertex count will be < 100 I'm looking for paths between a random subset of the vertices (at least 2). The paths should simple paths that only go through any vertex once. My end goal is to have a set of routes so that you can start at one of the subset vertices and reach any of the other subset vertices. Its not necessary to pass through all the subset nodes when following a route. All of the algorithms I've found (Dijkstra,Depth first search etc.) seem to be dealing with paths between two vertices and shortest paths. Is there a known algorithm that will give me all the paths (I suppose these are subgraphs) that connect these subset of vertices?

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