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  • Help C++ifying this C style code.

    - by Flamewires
    Hey I'm used to developing in C and I would like to use C++ in a project. Can anyone give me an example of how I would translate this C-style code into C++ code. I know it should compile in a c++ complier but I'm talking using c++ techniques(I.e. classes, RAII) typedef struct Solution Solution; struct Solution { double x[30]; int itt_found; double value; }; Solution *NewSolution() { Solution *S = (Solution *)malloc(sizeof(Solution)); for (int i=0;<=30;i++) { S-x[i] = 0; } S-itt_found = -1; return S; } void FreeSolution(Solution *S) { if (S != NULL) free(S); } int main() { Solution *S = NewSolution(); S-value = eval(S-x);// evals is another function that returns a double S-itt_found = 0; FreeSolution(S); return EXIT_SUCCESS; } Ideally I would like to be able to so something like this in main, but I'm not sure exactly how to create the class, i've read a lot of stuff but incorporating it all together correctly seems a little hard atm. Solution S(30);//constructor that takes as an argument the size of the double array S.eval();//a method that would run eval on S.x[] and store result in S.value cout << S.value << endl; Ask if you need more info, thanks.

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  • Help with AJAX, Using PHP and hiding elements.

    - by ryan
    Hey, This is my first time with AJAX, so I'm a bit confused and need your help. I have four div id's and want to toggle hide/show between them based on result from database. Sounds simple, eh! But it is hard to implement for me. HELP!. This is my code - <div id="1">HEya</div> <div id="2">What's up?</div> <input type="submit" id='approve' name="action" value="Approve" onclick="a()" class="approve" /> <input type="submit" id='reject' value="Reject" name="action" onclick="r()" class="reject"/> <script language="javascript" type="text/javascript"> //if cookie exists, at the beginning the form should be hidden if (<?php $responseanswer['response']=='approve'; ?> ){ document.getElementById('1').style.display = 'none'; document.getElementById('2').style.display = 'inline'; } //if user clicks reject, hide one element dislay another else if (<?php $responseanswer['response']=='reject'; ?>){ //if cookie exists document.getElementById('2').style.display = 'none'; document.getElementById('1').style.display = 'block'; } else { function a() { var a = document.getElementById('2'); document.getElementById('1').style.display= 'block'; } //on reject creating a new cookie function r() { var a = document.getElementById('reject'); document.getElementById('1').style.display = 'none'; document.getElementById('2').style.display= 'block'; } } </script> Eveything is fine, but the div is not hiding.

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  • Sending custom app logs to developer

    - by Templar
    I'm planning to release a new app in the future. I have a custom logging function which logs some application data (not crashes) into a file (location manager state, app foreground-background transitions, main actions...). These logs helped me a lot to debug problems which were app-related, but not causing a crash. Until now these were in the documents directory (shared in iTunes) and the testers sent them to me after they saw some incorrect behaviors, however I don't want to share them anymore because this directory contains the app's database too. I'd like to obtain these logs even when the app will be on App Store, but I don't know how this should be done. As I wrote, it is a new app and even after the test phase may exist minor bugs. I know that the users can report problems in iTunes or on the Dev site, but without a detailed scenario or log it is really hard to correct a bug. Should I make some kind of in-app bug report functionality (even if this creates a wrong user impression) ? How is this usually handled ? Thanks

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  • How to make Spring load a JDBC Driver BEFORE initializing Hibernate's SessionFactory?

    - by Bill_BsB
    I'm developing a Spring(2.5.6)+Hibernate(3.2.6) web application to connect to a custom database. For that I have custom JDBC Driver and Hibernate Dialect. I know for sure that these custom classes work (hard coded stuff on my unit tests). The problem, I guess, is with the order on which things get loaded by Spring. Basically: Custom Database initializes Spring load beans from web.xml Spring loads ServletBeans(applicationContext.xml) Hibernate kicks in: shows version and all the properties correctly loaded. Hibernate's HbmBinder runs (maps all my classes) LocalSessionFactoryBean - Building new Hibernate SessionFactory DriverManagerConnectionProvider - using driver: MyCustomJDBCDriver at CustomDBURL I get a SQLException: No suitable driver found for CustomDBURL Hibernate loads the Custom Dialect My CustomJDBCDriver finally gets registered with DriverManager (log messages) SettingsFactory runs SchemaExport runs (hbm2ddl) I get a SQLException: No suitable driver found for CustomDBURL (again?!) Application get successfully deployed but there are no tables on my custom Database. Things that I tried so far: Different techniques for passing hibernate properties: embedded in the 'sessionFactory' bean, loaded from a hibernate.properties file. Nothing worked but I didn't try with hibernate.cfg.xml file neither with a dataSource bean yet. MyCustomJDBCDriver has a static initializer block that registers it self with the DriverManager. Tried different combinations of lazy initializing (lazy-init="true") of the Spring beans but nothing worked. My custom JDBC driver should be the first thing to be loaded - not sure if by Spring but...! Can anyone give me a solution for this or maybe a hint for what else I could try? I can provide more details (huge stack traces for instance) if that helps. Thanks in advance.

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  • How to debug JBoss out of memory problem?

    - by user561733
    Hello, I am trying to debug a JBoss out of memory problem. When JBoss starts up and runs for a while, it seems to use memory as intended by the startup configuration. However, it seems that when some unknown user action is taken (or the log file grows to a certain size) using the sole web application JBoss is serving up, memory increases dramatically and JBoss freezes. When JBoss freezes, it is difficult to kill the process or do anything because of low memory. When the process is finally killed via a -9 argument and the server is restarted, the log file is very small and only contains outputs from the startup of the newly started process and not any information on why the memory increased so much. This is why it is so hard to debug: server.log does not have information from the killed process. The log is set to grow to 2 GB and the log file for the new process is only about 300 Kb though it grows properly during normal memory circumstances. This is information on the JBoss configuration: JBoss (MX MicroKernel) 4.0.3 JDK 1.6.0 update 22 PermSize=512m MaxPermSize=512m Xms=1024m Xmx=6144m This is basic info on the system: Operating system: CentOS Linux 5.5 Kernel and CPU: Linux 2.6.18-194.26.1.el5 on x86_64 Processor information: Intel(R) Xeon(R) CPU E5420 @ 2.50GHz, 8 cores This is good example information on the system during normal pre-freeze conditions a few minutes after the jboss service startup: Running processes: 183 CPU load averages: 0.16 (1 min) 0.06 (5 mins) 0.09 (15 mins) CPU usage: 0% user, 0% kernel, 1% IO, 99% idle Real memory: 17.38 GB total, 2.46 GB used Virtual memory: 19.59 GB total, 0 bytes used Local disk space: 113.37 GB total, 11.89 GB used When JBoss freezes, system information looks like this: Running processes: 225 CPU load averages: 4.66 (1 min) 1.84 (5 mins) 0.93 (15 mins) CPU usage: 0% user, 12% kernel, 73% IO, 15% idle Real memory: 17.38 GB total, 17.18 GB used Virtual memory: 19.59 GB total, 706.29 MB used Local disk space: 113.37 GB total, 11.89 GB used

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  • Java constructor using generic types

    - by Beer Me
    I'm having a hard time wrapping my head around Java generic types. Here's a simple piece of code that in my mind should work, but I'm obviously doing something wrong. Eclipse reports this error in BreweryList.java: The method breweryMethod() is undefined for the type <T> The idea is to fill a Vector with instances of objects that are a subclass of the Brewery class, so the invocation would be something like: BreweryList breweryList = new BreweryList(BrewerySubClass.class, list); BreweryList.java package com.beerme.test; import java.util.Vector; public class BreweryList<T extends Brewery> extends Vector<T> { public BreweryList(Class<T> c, Object[] j) { super(); for (int i = 0; i < j.length; i++) { T item = c.newInstance(); // breweryMethod() is an instance method // of Brewery, of which <T> is a subclass (right?) c.breweryMethod(); // "The method breweryMethod() is undefined // for the type <T>" } } } Brewery.java package com.beerme.test; public class Brewery { public Brewery() { super(); } protected void breweryMethod() { } } BrewerySubClass.java package com.beerme.test; public class BrewerySubClass extends Brewery { public BrewerySubClass() { super(); } public void brewerySubClassMethod() { } } I'm sure this is a complete-generics-noob question, but I'm stuck. Thanks for any tips!

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  • Stuck trying to get Log4Net to work with Dependency Injection

    - by Pure.Krome
    I've got a simple winform test app i'm using to try some Log4Net Dependency Injection stuff. I've made a simple interface in my Services project :- public interface ILogging { void Debug(string message); // snip the other's. } Then my concrete type will be using Log4Net... public class Log4NetLogging : ILogging { private static ILog Log4Net { get { return LogManager.GetLogger( MethodBase.GetCurrentMethod().DeclaringType); } } public void Debug(string message) { if (Log4Net.IsDebugEnabled) { Log4Net.Debug(message); } } } So far so good. Nothing too hard there. Now, in a different project (and therefore namesapce), I try and use this ... public partial class Form1 : Form { public Form1() { FileInfo fileInfo = new FileInfo("Log4Net.config"); log4net.Config.XmlConfigurator.Configure(fileInfo); } private void Foo() { // This would be handled with DI, but i've not set it up // (on the constructor, in this code example). ILogging logging = new Log4NetLogging(); logging.Debug("Test message"); } } Ok .. also pretty simple. I've hardcoded the ILogging instance but that is usually dependency injected via the constructor. Anyways, when i check this line of code... return LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); the DeclaringType type value is of the Service namespace, not the type of the Form (ie. X.Y.Z.Form1) which actually called the method. Without passing the type INTO method as another argument, is there anyway using reflection to figure out the real method that called it?

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  • How can I hardcode input with the "select" system call in C?

    - by Archer
    If I understand this system call "select" correctly, it will loop waiting for user input from the keyboard or from an outside server. Every time I call "message_loop", I'm going to type in the same few lines of input each time. Is there a way to hard code this in so I don't have to type it in each time? void message_loop(FILE* fpin, FILE* fpout, Socket sock) { fd_set readfds, readfds_bak ; int in, max_fd, n, ret ; char buf[MAXMESG]; in = fileno(fpin) ; FD_ZERO(&readfds) ; FD_SET(in, &readfds) ; FD_SET(sock.socketfd, &readfds) ; readfds_bak = readfds ; max_fd = ((in > sock.socketfd) ? in : sock.socketfd) + 1 ; while(1){ readfds = readfds_bak ; /* select function */ if((ret = select(max_fd, &readfds, NULL, NULL, NULL)) < 0){ perror("select") ; break ; } else if (ret != 0) { if(FD_ISSET(in, &readfds)){ /* keyboard input */ fgets(buf, MAXMESG, fpin) ; if(send_message(buf, sock) == -1) break ; } if(FD_ISSET(sock.socketfd, &readfds)){ /* messages from server */ n = receive_message(buf, MAXMESG, &sock) ; if(n == -1) break ; else if(n > 0){ fputs(buf, fpout) ; fputc('\n', fpout) ; } fflush(stdout) ; } } } }

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  • Connection Pool Strategy: Good, Bad or Ugly?

    - by Drew
    I'm in charge of developing and maintaining a group of Web Applications that are centered around similar data. The architecture I decided on at the time was that each application would have their own database and web-root application. Each application maintains a connection pool to its own database and a central database for shared data (logins, etc.) A co-worker has been positing that this strategy will not scale because having so many different connection pools will not be scalable and that we should refactor the database so that all of the different applications use a single central database and that any modifications that may be unique to a system will need to be reflected from that one database and then use a single pool powered by Tomcat. He has posited that there is a lot of "meta data" that goes back and forth across the network to maintain a connection pool. My understanding is that with proper tuning to use only as many connections as necessary across the different pools (low volume apps getting less connections, high volume apps getting more, etc.) that the number of pools doesn't matter compared to the number of connections or more formally that the difference in overhead required to maintain 3 pools of 10 connections is negligible compared to 1 pool of 30 connections. The reasoning behind initially breaking the systems into a one-app-one-database design was that there are likely going to be differences between the apps and that each system could make modifications on the schema as needed. Similarly, it eliminated the possibility of system data bleeding through to other apps. Unfortunately there is not strong leadership in the company to make a hard decision. Although my co-worker is backing up his worries only with vagueness, I want to make sure I understand the ramifications of multiple small databases/connections versus one large database/connection pool.

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  • multiple form submission with one submit

    - by skylab
    I've been trying to think this through and figure out if it is possible or not. I'm using zen-cart as shopping cart software, but what I'd like to do, is hard code a page that is basically a list of 7-9 products, next to each product is a checkbox, so I'd like to figure out a way, via html,javascript or jquery to submit whichever forms(products) are checked to the cart. The typical form submission for a product looks something like this(sometimes there may be one or two additional hidden fields): <form name="cart_quantity" action="index.php?action=add_product" method="post" enctype="multipart/form-data"> <input type="hidden" name="cart_quantity" value="1"> <input type="hidden" name="products_id" value="7"> <input type="hidden" name="id[6]" value="9" id="attrib-6-9"> <input type="image" src="buy_button.png" alt="Add to Cart" title="Instructional Video Part 1: Add to Cart"> </form> There would be 7-9 of these on the page, each with a checkbox, so I'm assuming a script would need to figure out which ones where checked and submit them via the form action? Maybe there is a better way of going about this that I'm not thinking of because a)it's over my head or b)just haven't figured it out yet. Anyway is something like this possible?

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  • How to catch unintentional function interpositioning with GCC?

    - by SiegeX
    Reading through my book Expert C Programming, I came across the chapter on function interpositioning and how it can lead to some serious hard to find bugs if done unintentionally. The example given in the book is the following: my_source.c mktemp() { ... } main() { mktemp(); getwd(); } libc mktemp(){ ... } getwd(){ ...; mktemp(); ... } According to the book, what happens in main() is that mktemp() (a standard C library function) is interposed by the implementation in my_source.c. Although having main() call my implementation of mktemp() is intended behavior, having getwd() (another C library function) also call my implementation of mktemp() is not. Apparently, this example was a real life bug that existed in SunOS 4.0.3's version of lpr. The book goes on to explain the fix was to add the keyword static to the definition of mktemp() in my_source.c; although changing the name altogether should have fixed this problem as well. This chapter leaves me with some unresolved questions that I hope you guys could answer: Should our software group adopt the practice of putting the keyword static in front of all functions that we don't want to be exposed? Does GCC have a way to warn about function interposition? We certainly don't ever intend on this happening and I'd like to know about it if it does. Can interposition happen with functions introduced by static libraries? Thanks for the help.

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  • Looking for Simplified Overview of EJB3

    - by sdoca
    Hi I'm looking for a simplified overview of EJB3 components. I seem to understand most of the pieces of the puzzle, but can't quite get them to fit together in my brain as a full picture. I've developed numerous web applications (wars) that have been deployed on Tomcat before, but not a full-fledged EE application (ear). I would like the overview to be as generic as possible. I'm not looking for a tutorial on how to set up EJB3 on Glassfish built in NetBeans or some other vendor specific tutorial that's more about the IDE than the technology. I keep reading about Java, ejb-jar, web and ear modules but am not clear on what these different modules contain and how to use them to put together my app. In my case, I want to write a simple database CRUD web application. The first step is simple; create entity classes that model the database tables my app will be using. I plan on using annotations. Should I create a jar that contains just these enity classes? Is this the ejb-jar module (sometimes referred to as the Java module)? Next, I'll need some business logic classes that make use of the entity classes. These are the session beans (stateless or stateful) correct? Should these be packaged in the same jar as the entity classes or a separate jar? Finally, I'll need some sort of web interface (I'll be creating a JSF portlet) application that makes use of the both the session and entity beans. Together with the above jar(s), this will be my war? Assuming the above to be correct, what is involved in creating an ear? Forgive me if this post is vague, but I'm having a hard time defining what it is I don't understand. Thanks for any help!

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  • Xcode 4: nib files not loading when run, can't find UI elements

    - by Jordan
    So, I just downloaded Xcode 4 and installed it. I was actually quite looking forward to the single window and integrated IB... - However, when I open and run one of my projects, the nib files that the project uses don't seem to load. Instead I'm left looking at a blank white screen (iPhone). This project ran well and fine on Xcode 3.2. So I thought... this can't be that hard to fix. So I opened up a nib file, thinking that maybe editing or creating a new one from scratch could point me in the right direction. But I can't find the old resources panel from interface builder anywhere. How am I meant to create a new view or add buttons? I know I'm probably just missing something obvious :s Did anyone else have the same nib file problems - is there a fix (or something stupidly simple that I'm forgetting about)? - EDIT: Ok. If I background and un-background the app, the view loads fine. But this happens every time I build, on both iPhone and iOS simulator, i.e. the app doesn't work properly until it's been backgrounded. All the code for loading the view follows from - (void)applicationDidFinishLaunching:(UIApplication *)application. Now I am really confused. - Thanks :)

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  • Typedef equivalence in function arguments

    - by Warren Seine
    Hi guys, The question is kind of hard to ask without an example so here it is: #include <vector> struct O { }; struct C { template <typename T> void function1(void (C::*callback)(const O*)); template <typename T> void function2(void (C::*callback)(const typename T::value_type)); void print(const O*); }; int main() { C c; c.function1< std::vector<O*> >(&C::print); // Success. c.function2< std::vector<O*> >(&C::print); // Fail. } The error that I am given is: error: no matching function for call to ‘C::function2(void (C::*)(const O*))’. Basically, the only difference between calls is that in function2, I'm more generic since I use the typedef std::vector<O*>::value_type which should resolve to O*, hence similar to function1. I'm using G++ 4.2.1 (I know it's old), but Comeau confirms I'm wrong. Why does the compilation fail?

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  • jquery dialog is clearing my form fields and I need to return a value from a jquery dialog

    - by Seth
    1.) I have a jQuery dialog that is opened whenever a particular textbox is focused. The dialog's contents are loaded from ajax and the unique ID of the textbox that was focused is passed in the ajax call (like this): $('[name=start_airport[]],[name=finish_airport[]]').click(function(){   var id = $(this).attr('id');   if($('#use_advanced_airport_selector').attr('checked')) {     $('#advanced_airport_selector').dialog({       open : function() {         $(this).load('/flight-booker/advanced-airport-selector.php?callerID='+id);       }     });     $('#advanced_airport_selector').dialog('open');   } }); (where advanced_airport_selector is an empty div) THAT PART WORKS FINE. However, when I make my ajax call within my dialog, all my form values are reset! No matter what I do, when that dialog opens, all form values are reset (not just the value of the textbox that was focused). I simply don't understand what would cause this behavior! But that's only issue #1. 2.) I need to be able to return a value from that dialog box. I am passing the ID in the ajax query so that I can use a jquery selector to update the caller's value after certain actions are performed within the dialog box. However, I can't actually access that textbox because of DOM_ERRORS that I've never come across. It doesn't make any sense! There's way to much code to post, and it's really hard to explain, so sorry if I'm unclear as to what I'm asking.

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  • Best way to organize a Go interface

    - by Metropolis
    Hey Everyone, Its been a long time since I have programmed in C++, and if I remember correctly the best way to organize classes was to create your class in the .h file, and then your implementation in your .cpp file. Well I am trying to learn Go now and I was reading over the Go for C++ Programmers article when I came upon interfaces. The article explains that interfaces in Go essentially take the place of classes, and shows how to set them up pretty well. What I am trying to figure out though is how should I organize an interface into files? For instance, should the interface be in one file while the implementation is in another? myInterface.go type myInterface interface { get() int set(i int) } myImplementation.go type myType struct { i int } func (p *myType) set(i int) { p.i = i } func (p *myType) get() int { return p.i } My code here may be wrong since I do not completely know what I am doing yet (and if I am wrong please correct me), but would this be the best way to set this up? Im having a very hard time trying to wrap my head around how to organize code in Go so any help is appreciated! Metropolis

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  • Java for loop with multiple incrementers

    - by user2517280
    Im writing a program which combines the RGB pixel values for 3 images, e.g. red pixel of image 1, green pixel of image 2 and blue pixel of image 3 and I want to then create a final image of it. Im using the code below, but this seems to be incrementing x2 and x3 whilst x1 is the same, i.e. not giving the right pixel value for same co-ordinate for each image. for (int x = 0; x < image.getWidth(); x++) { for (int x2 = 0; x2 < image2.getWidth(); x2++) { for (int x3 = 0; x3 < image3.getWidth(); x3++) { for (int y = 0; y < image.getHeight(); y++) { for (int y2 = 0; y2 < image2.getHeight(); y2++) { for (int y3 = 0; y3 < image3.getHeight(); y3++) { So I was wondering if anyone can tell me how to iterate through each of the 3 images on the same co-ordinate, so for example read 1, 1 of each image and record the red, green and blue value accordingly. Apologies if it doesnt make complete sense, its a bit hard to explain. I can iterate the values for one image fine but when I add in another, things start to go a bit wrong as obviously its quite a bit more complicated! I was thinking it might be easier to create an array and replace the according values in that just not sure how to do that effectively either. Thanks

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  • Algorithm to pick values from set to match target value?

    - by CSharperWithJava
    I have a fixed array of constant integer values about 300 items long (Set A). The goal of the algorithm is to pick two numbers (X and Y) from this array that fit several criteria based on input R. Formal requirement: Pick values X and Y from set A such that the expression X*Y/(X+Y) is as close as possible to R. That's all there is to it. I need a simple algorithm that will do that. Additional info: The Set A can be ordered or stored in any way, it will be hard coded eventually. Also, with a little bit of math, it can be shown that the best Y for a given X is the closest value in Set A to the expression X*R/(X-R). Also, X and Y will always be greater than R From this, I get a simple iterative algorithm that works ok: int minX = 100000000; int minY = 100000000; foreach X in A if(X<=R) continue; else Y=X*R/(X-R) Y=FindNearestIn(A, Y);//do search to find closest useable Y value in A if( X*Y/(X+Y) < minX*minY/(minX+minY) ) then minX = X; minY = Y; end end end I'm looking for a slightly more elegant approach than this brute force method. Suggestions?

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  • How to understand existing projects

    - by John
    Hi. I am a trainee developer and have been writing .NET applications for about a year now. Most of the work I have done has involved building new applications (mainly web apps) from scratch and I have been given more or less full control over the software design. This has been a great experience however, as a trainee developer my confidence about whether the approaches I have taken are the best is minimal. Ideally I would love to collaborate with more experienced developers (I find this the best was I learn) however in the company I work for developers tend to work in isolation (a great shame for me). Recently I decided that a good way to learn more about how experienced developers approach their design might be to explore some open source projects. I found myself a little overwhelmed by the projects I looked at. With my level of experience it was hard to understand the body of code I faced. My question is slight fuzzy one. How do developers approach the task of understanding a new medium to large scale project. I found myself pouring over lots of code and struggling to see the wood for the trees. At any one time I felt that I could understand a small portion of the system but not see how its all fits together. Do others get this same feeling? If so what approaches do you take to understanding the project? Do you have any other advice about how to learn design best practices? Any advice will be very much appreciated. Thank you.

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  • How to implement a grapher in C#

    - by iansinke
    So I'm writing a graphing calculator. So far I have a semi-functional grapher, however, I'm having a hard time getting a good balance between accurate graphs and smooth looking curves. The current implementation (semi-pseudo-code) looks something like this: for (float i = GraphXMin; i <= GraphXMax; i++) { PointF P = new PointF(i, EvaluateFunction(Function, i) ListOfPoints.Add(P) } Graphics.DrawCurve(ListOfPoints) The problem with this is since it only adds a point at every integer value, graphs end up distorted when their turning points don't fall on integers (e.g. sin(x)^2). I tried incrementing i by something smaller (like 0.1), which works, but the graph looks very rough. I am using C# and GDI+. I have SmoothingMethod set to AntiAlias, so that's not the problem, as you can see from the first graph. Is there some sort of issue with drawing curves with a lot of points? Should the points perhaps be positioned exactly on pixels? I'm sure some of you have worked on something very similar before, so any suggestions? While you're at it, do you have any suggestions for graphing functions with asymptotes? e.g. 1/x^2 P.S. I'm not looking for a library that does all this - I want to write it myself.

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  • Efficient Multiplication of Varying-Length #s [Conceptual]

    - by Milan Patel
    Write the pseudocode of an algorithm that takes in two arbitrary length numbers (provided as strings), and computes the product of these numbers. Use an efficient procedure for multiplication of large numbers of arbitrary length. Analyze the efficiency of your algorithm. I decided to take the (semi) easy way out and use the Russian Peasant Algorithm. It works like this: a * b = a/2 * 2b if a is even a * b = (a-1)/2 * 2b + a if a is odd My pseudocode is: rpa(x, y){ if x is 1 return y if x is even return rpa(x/2, 2y) if x is odd return rpa((x-1)/2, 2y) + y } I have 3 questions: Is this efficient for arbitrary length numbers? I implemented it in C and tried varying length numbers. The run-time in was near-instant in all cases so it's hard to tell empirically... Can I apply the Master's Theorem to understand the complexity...? a = # subproblems in recursion = 1 (max 1 recursive call across all states) n / b = size of each subproblem = n / 1 - b = 1 (problem doesn't change size...?) f(n^d) = work done outside recursive calls = 1 - d = 0 (the addition when a is odd) a = 1, b^d = 1, a = b^d - complexity is in n^d*log(n) = log(n) this makes sense logically since we are halving the problem at each step, right? What might my professor mean by providing arbitrary length numbers "as strings". Why do that? Many thanks in advance

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  • How do I become better in math, after being a programmer for several years.

    - by loxs
    I've had quite a weird career till now. First I graduated from a medical school. Then I went into marketing (pharmaceuticals). And then umm, after some time, I decided to go for my (till then) hobby and became a "professional" programmer. I've been quite successful at this ever since. I have quite some languages "under my belt". I earn not bad and I have been involved in the opensource community quite heavily. The thing is that I suck at math :). Well, not totally of course, as I get my work done. But I don't know how much I suck. And I don't know how to find out. Math has never really been of any priority during my middle/high school years. I only picked as little as I could afford, because I was always getting ready to go for Medicine. Of course I know the basics of algebra. Things like "normal" and square equations. Also the basics of geometry. But well, there are things that I have missed. And lately I am being fascinated by things like probability theory, infinity, chaos/order etc. But every time I try to learn something about these topics, I hit a wall of terminology, special symbols, and some special kind of thinking, that is quite like mine (a programmer), but also a lot different (and appears weird to me). So, what kinds of books would you recommend me? It's very hard to find something suitable. All that I find are either too easy (and boring) or totally impenetrable.

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  • Link compatibility between C++ and D

    - by Caspin
    D easily interfaces with C. D just as easily interfaces with C++, but (and it's a big but) the C++ needs to be extremely trivial. The code cannot use: namespaces templates multiple inheritance mix virtual with non-virtual methods more? I completely understand the inheritance restriction. The rest however, feel like artificial limitations. Now I don't want to be able to use std::vector<T> directly, but I would really like to be able to link with std::vector<int> as an externed template. The C++ interfacing page has this particularly depressing comment. D templates have little in common with C++ templates, and it is very unlikely that any sort of reasonable method could be found to express C++ templates in a link-compatible way with D. This means that the C++ STL, and C++ Boost, likely will never be accessible from D. Admittedly I'll probably never need std::vector while coding in D, but I'd love to use QT or boost. So what's the deal. Why is it so hard to express non-trivial C++ classes in D? Would it not be worth it to add some special annotations or something to express at least namespaces?

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  • Building a survey to put in a WordPress website using Python/Django

    - by chiurox
    So I've been given a task to build a survey to get data regarding time slot preferences of prospective students for a particular course. I know there are really quick solutions to this like Google Forms, SurveyMonkey, but since it's not unusually hard, I want to implement the survey myself in a totally new language as an opportunity to get started with it and also be able to customize and provide dynamic info to the users who are voting. Although I have done some stuff in PHP, C++, javascript, etc, I'm pretty new to Python+Django framework but it's something I've been meaning to get into since a long time ago. Initially, what I want is to make a grid with the days of the week as columns and time-durations as rows. In each cell I want to provide users a way to choose how strong (high/medium/low) their preference for this particular day+time is. I also want to show how many "votes" have already been cast for this particular preference because this will influence a lot in their decisions and as a result make this process easier when we are going to define the classes. I'll probably store the data in MySQL. Could anyone point me to some really good Python+Django tutorials for my particular purpose? Does anyone think I'm wasting my time with this trivial task by choosing new tools and that I should just use something I already know (like PHP) or a free service or plugin for Wordpress? Thanks!

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  • iFrame in a Content Editor Web Part

    - by Music Magi
    Hi - I'm creating a page with two web parts: one with a search UI and another that displays the results. I'm using Content Editor Web Parts for both, but no matter how hard I try I can't seem to display more than a fraction of the results page in the content editor web part with the iFrame. The width seems to set fine, but no matter how I set the height (I've tried in-line, using CSS and using Javascript/JQuery), I cannot change the height of what is displayed. If I make the height something ridiculous like 3000px, I can see the empty space below, but it still only shows a small amount of the resulting page at the top of this iframe section. I've observed the HTML and the iFrame takes up all the space it's supposed to, but only shows that small sliver of the actual page the iFrame is displaying. I've tried numerous approaches from numerous articles but have come up short (pun intended). Does anyone have any experience with this or have indication as to why it would display this way or what I have to do to make this iFrame fill up the entire web part space? Thanks in advance

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