Search Results

Search found 9706 results on 389 pages for 'aggregate functions'.

Page 257/389 | < Previous Page | 253 254 255 256 257 258 259 260 261 262 263 264  | Next Page >

• car and cdr in Scheme are driving me crazy ...

  - by kristian Roger

  Hi Im facing a problem with the car and cdr functions for example: first I defined a list called it x (define x (a (bc) d ( (ef) g ) )) so x now is equal to (a (bc) d ( (ef) g ) ) now for example I need to get the g from this list using only car and cdr (!! noshortcuts as caddr cddr !!) the correct answer is: (car(cdr(car(cdr(cdr(cdr x)))))) BUT how ? :-( I work according to the rules (the car gives the head of list and cdr gives the tail) and instead of getting the answer above I keep reaching wrong answers. Can any one help me in understanding this ... give me step or a way to solve it step by step Thanks in advance. I'm really sick of Scheme.

  Read the article

• How to join table to itself and select max values in SQL

  - by Jakub Konop

  I have a contracts table: contractId date price partId 1 20120121 10 1 2 20110130 9 1 3 20130101 15 2 4 20110101 20 2 The contract with greatest date being the active contract (don't blame me, I blame infor for creating xpps) I need to create query to see only active contracts (one contract per part, the contract with highest date). So the result of the query should be like this: contractId date price partId 1 20120121 10 1 3 20130101 15 2 I am out of ideas here, I tried self joining the table, I tried aggregation functions, but I can't figure it out. If anyone would have any idea, please share them with me..

  Read the article

• Is there a name for the technique of using base-2 numbers to encode a list of unique options?

  - by Lunatik

  Apologies for the rather vague nature of this question, I've never been taught programming and Google is rather useless to a self-help guy like me in this case as the key words are pretty ambiguous. I am writing a couple of functions that encode and decode a list of options into a Long so they can easily be passed around the application, you know this kind of thing: 1 - Apple 2 - Orange 4 - Banana 8 - Plum etc. In this case the number 11 would represent Apple, Orange & Plum. I've got it working but I see this used all the time so assume there is a common name for the technique, and no doubt all sorts of best practice and clever algorithms that are at the moment just out of my reach.

  Read the article

• Why use event listeners over function calls?

  - by Organiccat

  I've been studying event listeners lately and I think I've finally gotten them down. Basically, they are functions that are called on another object's method. My question is, why create an event listener when calling the function will work just fine? Example, I want to call player.display_health(), and when this is fired, the method player.get_health() should be fired and stored so that display_health() has access to it. Why should I use an event listener over simply calling the function? Even if display_health() were in another object, this still doesn't appear to be a problem to me. If you have another example that fits the usage better, please let me know. Perhaps particular languages don't benefit from it as much? (Javascript, PHP, ASP?)

  Read the article

• Setting creation or change timestamps

  - by Thanatos

  Using utimes, futimes, futimens, etc., it is possible to set the access and modification timestamps on a file. Is there a function to set change timestamps? (I understand the cyclic nature of wanting to change the change timestamp, but think archiving software - it would be nice to restore a file exactly as it was.) Are there any functions at all for creation timestamps? (I realize that ext2 does not support this, but I was wondering if Linux did, for those filesystems that do support it.) If it's not possible, what is the reasoning behind it not being so?

  Read the article

• Must a Language that Implements Monads be Statically Typed?

  - by Morgan Cheng

  I am learning functional programming style. From this link http://channel9.msdn.com/shows/Going+Deep/Brian-Beckman-Dont-fear-the-Monads/, Brian Beckman gave a brilliant introduction about Monad. He mentioned that Monad is about composition of functions so as to address complexity. A Monad includes a unit function that transfers type T to an amplified type M(T); and a Bind function that, given function from T to M(U), transforms type M(T) to another type M(U). (U can be T, but is not necessarily). In my understanding, the language implementing monad should be type-checked statically. Otherwise, type errors cannot be found during compilation and "Complexity" is not controlled. Is my understanding correct?

  Read the article

• How can I upload a file to a Sharepoint Document Library using Silverlight and client web-services?

  - by pclem12

  Most of the solutions I've come across for Sharepoint doc library uploads use the HTTP "PUT" method, but I'm having trouble finding a way to do this in Silverlight because it has restrictions on the HTTP Methods. I visited this http://msdn.microsoft.com/en-us/library/dd920295(VS.95).aspx to see how to allow PUT in my code, but I can't find how that helps you use an HTTP "PUT". I am using client web-services, so that limits some of the Sharepoint functions available. That leaves me with these questions: Can I do an http PUT in Silverlight? If I can't or there is another better way to upload a file, what is it? Thanks

  Read the article

• How to build third party libraries with Android NDK

  - by heiko.witte

  How can I compile third party libraries with the android NDK? I am compiling a wrapper which implements the JNI functions as a shared lib, which depends on another 3rd party lib (HTK). I don't know how to setup the makefile. The following does not work: LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) include HTKLib/Android.mk LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_MODULE := gaitfuncs LOCAL_SRC_FILES := gaitfuncs.c %LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog include $(BUILD_SHARED_LIBRARY) The second makefile should then build a static lib which my shared lib links to. How can I include this subdir makefile properly? Is this the correct way of doing it? And as a bonus: Are there wildcards for the LOCAL_SRC_FILES variable to take all files ending in .c for example. Thanks!

  Read the article

• is PHP itself transforming into a framework?

  - by Elzo Valugi

  At the beginning PHP was a scripting language. But after the introduction and improvement of OOP I see more and more objects added to the core. They started with SPL which grew a lot, now we have DOMDocument family, DateTime family which should be part of PECL, Pear or Zend Framework or implemented by each one of us. Shouldn't be php only for build-in functions and all these objects passed to something else? Example. DateTime class is part of the core and I see it very similar with Zend_Date.

  Read the article

• Help using the Office Interop for Word and Outlook 2007 in VB.NET

  - by vhorsen

  I need to start utilizing the interop in my programs to automate several functions in Word and Outlook and I was checking if anyone knew a good place to start. My ultimate goal is for my program to kick off a mail merge, create several different files and save them accordingly, then e-mail the different files to different people based upon who needs what. So any help on learning how to use the interop properly would be greatly appreciated. I am currently using Visual Studio 2008 and Office 2007 and use vb.net to write my programs. Thank you in advance.

  Read the article

• Facebook javascript in address bar, possible to replicate?

  - by DoMx

  This is my first experience with stackoverflow and I'm afraid my question asks of a lot for a first. I was looking at this thread: http://stackoverflow.com/questions/2634159/javascrypt-in-the-adress-bar-is-this-malicious and as you will see SLaks has very kindly deobfuscated the javascript and left us with what appears as the Javascript behind the automatic facebook invite code. As I'm fairly new to javascript, I was wondering, what other components were needed to get this code to work? You of course have the functions there and they are called by the obfuscated javascript but how exactly? Would it be possible to replicate this on a page of my own using the information available or is there more to this script I am missing? I am willing to financially assist somebody who could compile a solution for me. Thank you in advance.

  Read the article

• Is there a language designed for code golf?

  - by J S

  I am not really a fan of code golf, but I have to wonder, is there an esoteric language designed for it? I mean a language with following properties: Common programs may be expressed in very short amount of characters It uses ASCII character set effectively (for example, common operators are not identifiers, so they don't have to be separated by whitespace, character usage is distributed more or less evenly because we cannot use Huffman coding and so on) Except the terse syntax, it should have very expressible and clean semantics (like, let's say, Python or Scheme); it shouldn't be difficult to program in It doesn't need features for large scale programs, such as OOP, but it definitely should allow custom functions and data structures It should have a large standard library, identifiers in this library should be as short as possible Maybe it should be called CG? Languages that can be a source of inspiration are Forth, APL and Joy.

  Read the article

• Generating random numbers in C

  - by moonstruckhorrors

  While searching for Tutorials on generating random numbers in C I found This Topic When I try to use the rand() function with parameters, I always get the random number generated 0. When I try to use the rand() function with parameters, I always get the value 41. And whenever I try to use arc4random() and random() functions, I get a LNK2019 error. Here's what I'm doing: #include <stdlib.h> int main() { int x; x = rand(6); printf("%d", x); } This code always generate 41. Where am I going wrong?? P.S. : I'm running Windows XP SP3 and using VS2010 Command Prompt as compiler. P.P.S. : Took me 15 minutes to learn how to format properly.

  Read the article

• Is it possible to register a user and submit a comment with one form with Wordpress?

  - by zack

  Is it possible to do both registering for an account and submit a comment at the same time? I want the user to be able to do this all on one page to ecourage the registration rather than be discouraged about typing something, not realizing they had to be registered and thus having to leave the page. I think that this could be done by adding register user action to the submit comment action, but not sure how to do it with the prebuilt wordpress add_action or do_action functions. Has anyone tried this, or know of any plug-ins that do this already? I searched but couldn't find anything helpful. Thanks.

  Read the article

• Maintaining the query string in ASP.Net MVC

  - by Mantorok

  Hi all Just beginning my journey in ASP.Net MVC and I have a query about something before I dig myself in too deep. I have a table, which is paged, and I have 2 controls above the table: Dropdown that defines order of the results and apply button next to it Textbox that defines a filter and apply button next to it What I need to achieve is that if the user changes the order or adds a filter I fire of an AJAX call to my action like such: /Membership/Users?sort=value&filter=value&page=pagenumber. So my controller action is: // GET Membership/Users?sort=&filter=&page= public ActionResult Users(string sort, string filter, string page) So I have 3 questions: Is this the correct approach? What would be the best way to ensure that the query string is maintained, bearing in mind that the action will nearly always be called by Jquery/Ajax functions? If I wanted to link directly to this action passing the arguments would I need to hard-code the querystring? Thanks

  Read the article

• Is it bad practice to use python's getattr extensively?

  - by Wilduck

  I'm creating a shell-like environment. My original method of handleing user input was to use a dictionary mapping commands (strings) to methods of various classes, making use of the fact that functions are first class objects in python. For flexibility's sake (mostly for parsing commands), I'm thinking of changing my setup such that I'm using getattr(command), to grab the method I need and then passing arguments to it at the end of my parser. Another advantage of this approach is not having to update my (currently statically implemented) command dictionary every time I add a new method/command. My question is, will I be taking a hit to the efficiency of my shell? Does it matter how many methods/commands I have? I'm currently looking at 30 some commands, which could eventually double.

  Read the article

• Switching Javascript Function states

  - by webzide

  Dear experts, I would like to implement a API of Javascript that sort of resemble a light switch. For instance, there are two buttons on the actual HTML page act as the UI. Both of the buttons have event handlers that invokes a different function. Each function have codes that act like a state, for instance. button1.onclick=function (){ $("div").click( //code effects 2 ) } button2.onclick=function (){ $("div").click( //Code effects 2 ) } I the code works fine on the surface but the 2 state functions overlap. the effects is going to take place for the rest of the way until the next reload of the document. Basically what I want to achieve is that when 1 button is clicked, it will switch "OFF" the state of function invoked by the other button and vice versa. Thus, the effects achieved are unique are not overlapped. Is there anyway to achieve this or could any experts point me to the right direction. Thanks in advance.

  Read the article

• Registering a delegate function with an ISO C++ callback (on mono)

  - by Stick it to THE MAN

  I am thinking of wrapping ISO C++ code in C# class. The only problem so far is how to deal with the C++ callbacks. In .Net languages (C# and Vb.Net), I believe the callback equivalent. Sticking with C# for now, can anyone recommend a way that I can register the C# delegate functions with my ISO C++ code. The ISO C++ code is a notification library, and I want to be able to "push" the notifications to the mono framework (i.e. C# delegates in this case). My underlying assumption is that the mechanism/steps to implement this would be the same for the .Net languages - I'll just have to code the actual delegates in the .Net language of choice - is that assumption correct? Last but not the least, is the question of thread saftey. The underlying ISO C++ code that I am exposing to .Net (mono to be more specific), is both re-ntrant and thread safe - do I have to do anything "extra" to call .Net delegate from my ISO C++ code?

  Read the article

• What are Class methods in Python for?

  - by Dave Webb

  I'm teaching myself Python and my most recent lesson was that Python is not Java, and so I've just spent a while turning all my Class methods into functions. I now realise that I don't need to use Class methods for what I would done with static methods in Java, but now I'm not sure when I would use them. All the advice I can find about Python Class methods is along the lines of newbies like me should steer clear of them, and the standard documentation is at its most opaque when discussing them. Does anyone have a good example of using a Class method in Python or at least can someone tell me when Class methods can be sensibly used?

  Read the article

• Should I use C++0x Features Now?

  - by svu2g

  With the official release of VS 2010, is it safe for me to start using the partially-implemented C++0x feature set in my new code? The features that are of interest to me right now are both implemented by VC++ 2010 and recent versions of GCC. These are the only two that I have to support. In terms of the "safety" mentioned in the first sentence: can I start using these features (e.g., lambda functions) and still be guaranteed that my code will compile in 10 years on a compiler that properly conforms to C++0x when it is officially released? I guess I'm asking if there is any chance that VC++ 2010 or GCC will end up like VC++ 6; it was released before the language was officially standardized and consequently allowed grossly ill-formed code to compile. After all, Microsoft does say that "10 is the new 6". ;)

  Read the article

• In Python, how to use a C++ function which returns an allocated array of structs via a ** parameter?

  - by Jon-Eric

  I'd like to use some existing C++ code, NvTriStrip, in a Python tool. SWIG easily handles the functions with simple parameters, but the main function, GenerateStrips, is much more complicated. What do I need to put in the SWIG interface file to indicate that primGroups is really an output parameter and that it must be cleaned up with delete[]? /////////////////////////////////////////////////////////////////////////// // GenerateStrips() // // in_indices: input index list, the indices you would use to render // in_numIndices: number of entries in in_indices // primGroups: array of optimized/stripified PrimitiveGroups // numGroups: number of groups returned // // Be sure to call delete[] on the returned primGroups to avoid leaking mem // bool GenerateStrips( const unsigned short* in_indices, const unsigned int in_numIndices, PrimitiveGroup** primGroups, unsigned short* numGroups, bool validateEnabled = false ); FYI, here is the PrimitiveGroup declaration: enum PrimType { PT_LIST, PT_STRIP, PT_FAN }; struct PrimitiveGroup { PrimType type; unsigned int numIndices; unsigned short* indices; PrimitiveGroup() : type(PT_STRIP), numIndices(0), indices(NULL) {} ~PrimitiveGroup() { if(indices) delete[] indices; indices = NULL; } };

  Read the article

• how to control a embedded multiframe swf file?

  - by liuliu

  [Embed(source="data/fire.swf")] static public var movieFire:Class; I have some multiframe swf file and I want to have control of them. For example, I can use gotoandplay and gotoandstop functionality. I tried something like: var m:MovieClip = new movieFire() as MovieClip; but it turns out when I tried to get totalFrames, m.totalFrames, it gives me zero, and gotoand* functions don't work either. How can I correctly control the swf file embedded in actionsript 3.0 (No Flex component)?

  Read the article

• Style of if: to nest or not to nest

  - by Marco

  A colleague of mine and me had a discussion about the following best-practice issue. Most functions/methods start with some parameter checking. I advocate the following style, which avoids nesting. if (parameter one is ugly) return ERROR; if (parameter two is nonsense || it is raining) return ERROR; // do the useful stuff return result; He, who comes from a more functional/logic programming background, prefers the following, because it reduces the number of exit points from the function. if (parameter one is ok) { if (parameter two is ok && the sun is shining) { // do the useful stuff return result } } return ERROR; Which one would you prefer and why?

  Read the article

• Dealing with passwords securely

  - by Krt_Malta

  Hi I have a Java web service and a Java web client making use of this service. One of the functions is to create a new user account. My two concerns are: How will I send the user's password securely from the client. How will I store the user's password securely on the server. How can I achieve these? I know the theory basically behind security, security algorithms etc but can anyone give me some advice on how I should go about in coding? Could anyone point me to some good (and if possible not complicated) examples to follow since I found some examples on the Internet very contorted? Thanks a lot and regards, Krt_Malta

  Read the article

• Webservice and ORM Framework?

  - by Sebastian

  Does anybody know a good web framework that includes an ORM mapper and allows straight forward implementation of web services? I'm looking for a framework written in PHP or C++. I'm looking for the following features (not all of them required, some will do nicely) data definition in one place used by database and web service WSDL generation XML output/JSON output boilerplate code generation So what I would like is a framework that let's me specify the objects, the web service functions on those objects and then generate everything that is required leaving me to fill the business logic (connecting the database to the web service). Anything like that out there? Background information for why I need this: I'm looking into creating a web project: the client is a rich web application that fetches all its data using AJAX. It will be completely custom made using only a low level javascript library. The server back end is supposed to serve static content and javascript (basically the rich web application) and to provide a RESTful web service API (which I would like to implement using aforementioned framework).

  Read the article

< Previous Page | 253 254 255 256 257 258 259 260 261 262 263 264  | Next Page >