Search Results

Search found 4685 results on 188 pages for 'cpp beginner'.

Page 48/188 | < Previous Page | 44 45 46 47 48 49 50 51 52 53 54 55  | Next Page >

  • The conceptual process of populating related tables in a database (MySql) from a CSV file

    - by user322772
    I'm new to relational databases and all the material I've read covered primary and foreign keys, normal forms, and joins but left out to populate the database once it's created. How do you import a CSV file so the fields match their related table? Say you were tying to build a beer database and had a CSV file with each line as a record. Header: brewer, beer_name, country, city, state, beer_category, beer_type, alcohol_content Record 1: Anheuser-Busch, Budweiser, United States, St. Louis, Mo, Pale lager, Regular, 5.0% Record 2: Anheuser-Busch, Bud Light, United States, St. Louis, Mo, Pale lager Light, 4.2% Record 3: Miller Brewing Company, Miller Lite, United States, Milwaukee, WI, Pale lager, Light, 4.2% You can create a "Brewer" table and a "Beer" table. When importing how does you connect the primary keys between the tables?

    Read the article

  • How do I optimize this postfix expression tree for speed?

    - by Peter Stewart
    Thanks to the help I received in this post: I have a nice, concise recursive function to traverse a tree in postfix order: deque <char*> d; void Node::postfix() { if (left != __nullptr) { left->postfix(); } if (right != __nullptr) { right->postfix(); } d.push_front(cargo); return; }; This is an expression tree. The branch nodes are operators randomly selected from an array, and the leaf nodes are values or the variable 'x', also randomly selected from an array. char *values[10]={"1.0","2.0","3.0","4.0","5.0","6.0","7.0","8.0","9.0","x"}; char *ops[4]={"+","-","*","/"}; As this will be called billions of times during a run of the genetic algorithm of which it is a part, I'd like to optimize it for speed. I have a number of questions on this topic which I will ask in separate postings. The first is: how can I get access to each 'cargo' as it is found. That is: instead of pushing 'cargo' onto a deque, and then processing the deque to get the value, I'd like to start processing it right away. I don't yet know about parallel processing in c++, but this would ideally be done concurrently on two different processors. In python, I'd make the function a generator and access succeeding 'cargo's using .next(). But I'm using c++ to speed up the python implementation. I'm thinking that this kind of tree has been around for a long time, and somebody has probably optimized it already. Any Ideas? Thanks

    Read the article

  • How to turn off startup text of GNU gdb in XCode

    - by willc2
    I'm new to XCode 3.1.2 and Objective-C 2.0. I've just discovered using breakpoints for logging instead of littering the code with millions of NSLog() statements. The problem is, when the debugger starts up it spews half a screen full of status and credits info into the console. Is there any way to suppress this text?

    Read the article

  • split twice in the same expression?

    - by UcanDoIt
    Imagine I have the following: inFile = "/adda/adas/sdas/hello.txt" # that instruction give me hello.txt Name = inFile.name.split("/") [-1] # that one give me the name I want - just hello Name1 = Name.split(".") [0] Is there any chance to simplify that doing the same job in just one expression?

    Read the article

  • Active Record like functionality on array instance variable

    - by rube_noob
    I would like to write a module that provides active record like functionality on an array instance variable. Examples of its use would be x = Container.new x.include(ContainerModule) x.elements << Element.new x.elements.find id module ContainerModule def initialize(*args) @elements = [] class << @elements def <<(element) #do something with the Container... super(element) end def find(id) #find an element using the Container's id self #=> #<Array..> but I need #<Container..> end end super(*args) end end The problem is that I need the Container object within these methods. Any reference to self will return the Array, not the Container object. Is there any way to do this? Thanks!

    Read the article

  • How to learn a language that has very little coverage?

    - by bennybdbc
    I recently came across the Kogut language, and was interested by it. However, the only website to gain information from is the sourceforge page that hosts the project. I had no idea how to even attempt to look at the language in more depth. So what I'm asking is, has anyone here learnt a language that doesn't have the thousands of resources that Ruby, Python etc. have? What would be the best method to do so?

    Read the article

  • How do I keep from running out of memory on graphics for an Android app?

    - by user279112
    I've been working on an Android app in Eclipse, and so far, my program hasn't really grown past midget size. However I've already run into an issue with an Out of Memory error. You see, I've been using graphics comprised solely of bitmaps and PNGs in this program, and recently, when I tried to add a little bit more functionality to the program (mainly including a few more bitmaps and causing an extra sprite to be created), it started crashing in the graphics thread's constructor - sprite's constructor. When I tracked the problem down, it turned out to be an Out of Memory error that is seemingly caused by adding too many picture files to the program and creating Drawables out of them. This would be a problem, as I really don't have that many picture resources worked into that program...maybe 20 or so. I haven't even started to include sound yet. These images aren't all that fancy. My questions are this: 1) Are programs for the Android phone really that limited on how much memory they can employ, or is it probably something other than the 20-30 resource pictures causing that error? 2) If the memory for Android apps is so awful it can't even handle 20-30 picture resources being loaded into Drawables that exist at the same time, then how in the world are you supposed to make decent graphics and sound for that thing? Thanks.

    Read the article

  • C# Using singleton instead of a global static instance

    - by Farstucker
    I ran into a problem today and a friend recommended I use a global static instance or more elegantly a singleton pattern. I spent a few hours reading about singletons but a few things still escape me. Background: What Im trying to accomplish is creating an instance of an API and use this one instance in all my classes (as opposed to making a new connection, etc). There seems to be about 100 ways of creating a singleton but with some help from yoda I found some thread safe examples. ..so given the following code: public sealed class Singleton { public static Singleton Instance { get; private set; } static Singleton() { Instance = new Singleton(); } } How/Where would you instantiate the this new class and how should it be called from a separate class? Thanks for your help.

    Read the article

  • Suggest resources for learning Scheme.

    - by EmFi
    I'll be starting a new job soon where Scheme is heavily used. I currently do not know Scheme, but my employer assures me that is not a problem. Regardless I'd like to hit the ground running and have a working knowledge of the language before my start date. So I'm looking for good resources from which to learn Scheme. I have had minimal exposure to functional languages. Really only a small chunk of a course devoted to Haskell. But I have a strong background in procedural and OO and procedural languages. Before it gets requested by a commenter, I am competent with the following languages: C, C++, C#, Java, Perl, Python, and Ruby.

    Read the article

  • importing class and its function from another file

    - by user343934
    Hi everyone, I am having little problem with importing classes in python. My work flow goes like this index.py class Template: def header(): def body(): def form(): def footer(): display.py I want to call function header(), body() and footer () in my display.py page. Will anyone make me clear about this issue in python. Thanks for your concern.

    Read the article

  • Applications of Unification?

    - by Ravi
    What are (practical) applications of Unification ? Where it is been used in real world? I couldn't get the whole idea of what it is really about and why its considered as a part of Artificial Intelligence.

    Read the article

  • "_FILE_AND_LINE_ is not defined in this scope" (compiling RakNet NAT examples in OS X)

    - by Michael F
    Hello! I'm working on a RakNet-based project (using 3.8 on OS X 10.6), and I'm trying to work through the various examples that demonstrate the parts of RakNet I want to use. For the "NatCompleteClient" example, I've imported the source into a command-line project in XCode, along with the UPNP dependency. At compile time I've had a few errors in the UPNP section, though, and I can't find any guidance on this. In UPNPPortForwarder.mm, there are 7 lines that use _FILE_AND_LINE_, and the compiler is not happy; for example on line 232: foundInterfaces.Deallocate(r1,_FILE_AND_LINE_); causes: UPNPPortForwarder.mm:232: error: '_FILE_AND_LINE_' was not declared in this scope Can anyone tell me what this is all about? That variable doesn't seem to get talked about very often... or Google doesn't like to find it.

    Read the article

  • resetting the image in an NSView

    - by Josan
    I think this is a very simple question, but I’m new to programming so I may be going about it in a wrong-headed way. I have a basic understanding of Objective-C writing terminal applications and am teaching myself how to use the Cocoa GUI. I understand how to use IBOutlet and IBAction to connect a simple button to a method that will repeatedly send random numbers to a textfield . I understand how to add a NSView file, connect it to a custom view in interface builder and draw a path through random points in the view when the application launches. (I’ve been putting this code inside the - (void)drawRect:(NSRect)dirtyRect method that is declared when the file is created). What I can’t seem to figure out is how to connect a button to an action that will then ‘refresh’ the view – in this case repopulate it with another set of random points connected with a path. Looking at the documentation, I think I should somehow be using – (void) setNeedsDisplay(BOOL)flag but nothing I have tried so far had worked. Please tell me, what am I missing here?

    Read the article

  • accing a fortran 'module' in a 'function defined in some other file

    - by cppb
    hello, I am using fortran 90 I have defined a fortran module in fileA.f as: module getArr double precision a(100) end module getArr The same fileA.f contains a subroutine that uses this module subroutine my_sub use getArr implicit none getArr%a(1) = 10.5 end subroutine In fileB.f, I have a fortrtan function. I am trying to access the value of getArr%a(1) as: double precision function my_func(R) use getArr double precision x x = getArr%a(1) return end But I am getting errors at the compile time. It says it is unable to access the module getArr. How should I declare it?? Thanks

    Read the article

  • Background Image w/Quartz Drawing

    - by James
    I'm using Quartz to do some basic drawing. I recently decided I wanted a background image for my app. So I went into my XIB file and added a UIImageView and set the background, looks good. However, when I run it, the Z-Index of the image is above my drawing. I googled a bit and found that you can do Layout Send to Back in IB...but that option is grayed out to me when I have my UIImageView selected. Is there an easy way to move this UIImageView permanently to the background? Is there perhaps an alternate method to doing this that I should consider? Thanks

    Read the article

  • Why do I get "mysql_query(): supplied argument is not a valid"

    - by Brian Ojeda
    Why do I get a "mysql_query(): supplied argument is not a valid" for the first... $r = mysql_query($q, $connection); In the following code... $bId = trim($_POST['bId']); $title = trim($_POST['title']); $story = trim($_POST['story']); $q = "SELECT * "; $q .= "FROM " . DB_NAME . ".`blog` "; $q .= "WHERE `blog`.`id` = {$bId}"; $r = mysql_query($q, $connection); //confirm_query($r); if (mysql_num_rows($r) == 1) { $q = "UPDATE " . DB_NAME . ".`blog` SET `title` = '{$title}', `story` = '{$story}' WHERE `id` = {$bId}"; $r = mysql_query($q, $connection); if (mysql_affected_rows() == 1) { //Successful $data['success'] = true; $date['errors'] = false; $date['message'] = "You are the Greatest!"; } else { //Fail $data['success'] = false; $data['error'] = true; $date['message'] = "You can't do it fool!"; } } I also get an "mysql_num_rows(): supplied argument is not a valid MySQL result resource" error too. Side notes: I am using 1&1 Hosting (worst hosting ever), custom .htaccess file with one line text to enable PHP 5.2 (only why with 1&1 Hosting).

    Read the article

  • creation of folders in python

    - by beena shamsudeen
    i want to create folders with the name of a pdf file for eg,abc.if it does not exists,i should create a folder with name abc_1...if abc_1 exists,i shud create abc_2.if both exxists,abc_3 and so on...the scripting is in python..can u help me??

    Read the article

  • Is C++ (one of) the best language to learn at first

    - by AlexV
    C++ is one of the most used programming language in the world since like 25+ years. My first job as programmer was in C++ and I coded in C++ everyday for nearly 4 years. Now I do mostly PHP, but I will forever cherish this C++ background. C++ has helped me understand many "under the hood" features/behaviors/restrictions of many other (and different) programming languages like PHP and Delphi. I'm a full time programmer for 6+ years now and since I have a quite varied programming background I often get questions by "newbies" as where to start to become a "good" programmer. I think C++ is one of the best language to start with because it gives you a real usefull experience that will last and will teach you how things work under the hood. It's not the easier one to learn for a newbie, but in my opinion it's one that will reward in the long term. I would like to know your opinion on this matter to add to my arguments when I guide "newbies". After this introduction, here's my question : Is C++ (one of) the best language to learn at first for you. Since it's subjective, I've marked this question as community wiki. EDIT: This question is not about why Java (or C# or any other language) is better than C++ to start with, it's about what's make C++ a good choice or not a good choice to learn as one of your firsts languages. For example, for me C++ made me understand how the memory works. Now today in many languages everything is managed by the garbadge collector and some people don't even know that. I'm glad I know how it works underneath and I think it can help you to write better code.

    Read the article

  • Which Ipod touch generation should I buy? 2nd or 3rd?

    - by kukabunga
    I want to create games for Iphone/Ipod touch. Unfortunately I don't have a lot of money so I can buy only one device. Ipod is cheaper than Iphone, so I decided to bought Ipod touch. But I am afraid of buying 3rd generation - because it has more memory, more faster CPU, etc. And I think if I post my app on appstore - people with 2nd generation Ipod might have trouble with my app (because I was testing it on 3rd generation). But on the other hand - I am planning to create 3d/cpu demanding game - and it would be easy for me to implement it on device with more calculation power... What should I do in this situation? Any advice is appreciate.

    Read the article

  • How to create reusable WPF grid layout

    - by zendar
    I have a window with tab control and number of pages - tab items. Each tab item has same grid layout - 6 rows and 4 columns. Now, each tab item contains grid with row and column definitions, so almost half of XAML is definition of grids. How can I define this grid in one place and reuse that definition in my application? Template? User control? Besides 6x4, I have only two more grid dimensions that repeat: 8x4 and 6x6.

    Read the article

< Previous Page | 44 45 46 47 48 49 50 51 52 53 54 55  | Next Page >