Search Results

Search found 13225 results on 529 pages for 'dynamic variables'.

Page 220/529 | < Previous Page | 216 217 218 219 220 221 222 223 224 225 226 227  | Next Page >

• 0/1 Knapsack with irrational weights

  - by user356106

  Consider the 0/1 knapsack problem. The standard Dynamic Programming algorithm applies only when the capacity as well as the weights to fill the knapsack with are integers/ rational numbers. What do you do when the capacity/weights are irrational? The issue is that we can't memoize like we do for integer weights because we may need potentially infinite decimal places for irrational weights - leading to an infinitely large number of columns for the Dynamic Programming Table . Is there any standard method for solving this? Any comments on the complexity of this problem? Any heuristics? What about associated recurrences like (for example): f(x)=1, for x< sqrt(2) f(x)=f(x-sqrt(2))+sqrt(3)

  Read the article

• algorithm to combine data for linear fit?

  - by BoldlyBold

  I'm not sure if this is the best place to ask this, but you guys have been helpful with plenty of my CS homework in the past so I figure I'll give it a shot. I'm looking for an algorithm to blindly combine several dependent variables into an index that produces the best linear fit with an external variable. Basically, it would combine the dependent variables using different mathematical operators, include or not include each one, etc. until an index is developed that best correlates with my external variable. Has anyone seen/heard of something like this before? Even if you could point me in the right direction or to the right place to ask, I would appreciate it. Thanks.

  Read the article

• PHP Possible Memory Leak

  - by dropson

  I have a script that loops through a database for images to convert with gd & imagick. I unset or replace all variables and objects in between each loop. For each loop, get_memory_usage(1) reveals a concurrent amount of memory used by that script. Which is expected. But, when I run "top", the %MEM column reports that this script, (same PID), increments with several percentages for each loop. I destroy all images when I'm done with them, and when I run get_defined_vars(); only the standard globals and a few variables I have is set. Why is "top" % Memory Usage different than what PHP reports? After 10 loops, PHP has taken 20% percetage of the system memory. I run php 5.2.6 on Debian 5

  Read the article

• URIs vs Hidden Forms

  - by NateDogg

  I'm working in the Codeigniter framework, and want to send requests to my controller/model that have several variables involved. Is there a difference between passing those variables via a hidden form (i.e. using "post") as opposed to passing them through URIs (e.g. 'travel/$month/$day/')? What about security concerns? e.g. URIs: http://www.example.com/travel/$month/$day/ Hidden Form: form_hidden('month',$month); form_hidden('day',$day);

  Read the article

• Android -- Object Creation/Memory Allocation vs. Performance

  - by borg17of20

  Hello all, This is probably an easy one. I have about 20 TextViews/ImageViews in my current project that I access like this: ((TextView)multiLayout.findViewById(R.id.GameBoard_Multi_Answer1_Text)).setText(""); //or ((ImageView)multiLayout.findViewById(R.id.GameBoard_Multi_Answer1_Right)).setVisibility(View.INVISIBLE); My question is this, am I better off, from a performance standpoint, just assigning these object variables? Further, am I losing some performance to the constant "search" process that goes on as a part of the findViewById(...) method? (i.e. Does findsViewById(...) use some sort of hashtable/hashmap for look-ups or does it implement an iterative search over the view hierarchy?) At present, my program never uses more than 2.5MB of RAM, so will assigning 20 or so more object variables drastically affect this? I don't think so, but I figured I'd ask. Thanks.

  Read the article

• Server-side access to Client Browser's Latitude/Longitude using Django.

  - by ZenGyro

  Hello, So i am writing a little app that compares a user's position against a database on web-based server written using Django and performs some functions with it. Accessing the browser's geolocation data (in supported browsers ) is fairly trivial using JavaScript. But what is the best way to allow the Django server to access the longitude and latitude variables? Is it best to wrap them up as a JSON object and send to the server via POST? Or is there some easier (Geo)Django-based way to access the Navigator.geolocation browser object. Please forgive a newbie a question like this, but my Google-Fuing only seems to find ways to insert variables into JavaScript via template tag, whereas I need it to work the other way! Any advice or code snippets greatly appreciated. Feel free to talk to me like I am an idiot.

  Read the article

• C++ Interpreter: How to emit error messages?

  - by Rawr

  I want to emit dynamic error messages like all interpreters do nowadays, for example: Name error: Undefined variable would be constant, however what I want to reach is: Name error: Undefined variable 'X', in line 1 Okay. The line number was really no problem: Every error message must have a line number, so I added it to the error emitter function: Error( ErrType type, string msg, int line ); So where is my problem? How do I get the 'X' into Undefined variable *? I can't use sprintf as it doesn't support strings yet I use them everywhere I can't simply use cout and connect everything as I want error messages to be supressable I'd like to get everything into one function like above, Error() How do I put together dynamic error messages? For example: Error( Name, sprintf("Undefined variable %s", myVariableName ), lineNum ); (But myVariableName is a string and sprintf will mess things up)

  Read the article

• Do you use another language instead of english ?

  - by Luc M

  Duplicate Should identifiers and comments be always in English or in the native language of the application and developers? For people who are not native English speakers, which language do you use to declare variables, classes, etc. ? I had to continue a project from a Spanish guy. Everything was written in Spanish. Since this time, I have decided to use English identifiers ( variables, classes, file names) and write comments in french. Everything was in french before that. What are the general recommendations about that practice? Do you use English everywhere knowing that no English people will work on your project ? Edit : Here's a post from Jeff Atwood about this subject: The Ugly American Programmer

  Read the article

• Handling JSON and HTML templates in jQuery

  - by Toby Hede

  I have an ajax-enabled site that presents a lot of dynamic content by interpolating JSON values with HTML. This all works fine. BUT it means I have significant amounts of HTML all through my JavaScript. For example: var template = "<div>Foo: {bar}</div><div>Blah: {vtha}</div>"; template.interpolate({bar:"bar",blah:"vtha"}); I have cut this down a fair bit - some of my dynamic elements have quite a lot of HTML and a lot going on. I am using jQuery and I am building on Rails, so if there is something smart in either framework, that would be great. For reference, the String interpolation function used above is: String.prototype.interpolate = function (o) { return this.replace(/{([^{}]*)}/g, function (a, b) { var r = o[b]; return typeof r === 'string' || typeof r === 'number' ? r : a; } ); };

  Read the article

• Kernel dealing with the section headers in an ELF

  - by uki

  I recently read that the kernel and the dynamic loader mostly deal with the program header tables in an ELF file and that assemblers, compilers and linkers deal with the section header tables. The number of program header tables and section header tables are mentioned in the ELF header in fields named e_phnum and e_shnum respectively. e_phnum is two bytes in size, so if the number of program headers is 65535, we use a scheme known as extended numbering where, e_phnum is set to 0xffff and sh_link field of the zeroth section header table holds the actual count. My doubt is : If the count of program headers exceeds 65535, does that mean the kernel and/or the dynamic loader end up having to read the section table?

  Read the article

• Keep a javascript variable after an ajax call

  - by Guillaume le Floch

  I'm new in javascript and jQuery. I'm using ajax calls to get data from my server. The fact is, I'm losing my javascript variables after the call .. Here is what I did : the variable is define outside any function and treat in an other function. var a = 0; function myfunction(url){ $.ajax({ url: url, timeout: 20000, success: function(data){ // Do some stuff // The a variable is now undefined }, error: function(){ // Do some stuff } }); } Everything is working fine, the only thing is that I need to keep my variables ... but it looks like it's gone .. Does anyone know why? Thanks

  Read the article

• Write to a binary file?

  - by rick irby

  Here is data structure w/ variables: struct Part_record { char id_no[3]; int qoh; string desc; double price: }; --- (Using "cin" to input data) --- Part_record null_part = {" ", 0," ",0.0}; --- --- file.seekg( -(long)sizeof(Part_record), ios::cur); file.write( ( char *)&part, sizeof(Part_record) ); The three variables, qoh, Id_no & price, write out correctly, but the "desc" variable is not right. Do I need to initialize Part_record some other way? It should be 20 characters in length. If you have enough info here, pls share your advice,thanks.

  Read the article

• Ant Exec environment var

  - by Mike

  I have a problem where I don't want to have to call a setEnv.sh file before i call my ant target that calls an exec task. Right now I have a way to save the environment variables in setenv.properties file in the key=value notation. The exec task for some reason does not see the variables that are set in the .properties file.... (I know i could use the tag but the setenv.properties is dynamically generated) setenv.properties: HELLO=XYZ part of my build.xml : <property file="setenv.properties"/> <target name="test" depends="setEnv"> <exec executable="/bin/ksh" newenvironment="false"> test.sh : echo ${HELLO} Any thoughts?

  Read the article

• How to dynamically change fields in an .NET ORM

  - by rsteckly

  I'm working in ASP.NET in an application where often users want to add fields or change field names. I'd like to be able to have an xml schema in place that is parsed and a dynamic object model created from it that can be accessed throughout the application. My initial reaction is that this is not realistic. I think there is flexibility about the dynamic nature of it. I think the people I'm trying to build this for wouldn't mind recompiling. Even if the app recompiled, I don't know how to abstract away enough in my code access the data to allow for users changing property names, etc. How can you write LINQ when the properties might change? In short, there's two questions here: 1) is there a way to dynamically generate an object model of the database and 2) is there a way to abstract away enough so that code accessing the database doesn't break when properties change?

  Read the article

• Check if a variable is empty

  - by Thomas

  I have some user-submitted variables that I want to display in a different part of my site like this: <div class="pre_box">Term: </div> <div class="entry"><?php $key='term'; echo get_post_meta($post->ID, $key, true); ?></div> Occasionally, these variables might be empty in which case I don't want to display the label for the empty variable. In the example above I would want to hide the <div class="pre_box">Term: </div> part. Is there some simple way to check if a php variable like the one above is empty and prevent the label from being displayed?

  Read the article

• Why use constants in programming?

  - by Adam N

  I've just been going back over a bit of C studying using Ivor Horton's Beginning C book. I got to the bit about declaring constants which seems to get mixed up with variables in the same sentence. Just to clarify, what is the difference in specifying constants and variables in C, and really, when do you need to use a constant instead of a variable? I know folks say to use a constant when the information doesn't change during program execution but I can't really think of a time when a variable couldn't be used instead. Thanks

  Read the article

• Is there a better way to do SELECT queries in MySQL and sort them in PHP than this way?

  - by Kent

  I am just learning PHP/MySQL, one this I am having to do a lot is displaying data that was previously inserted into the database out to the user's browser. So I am doing this: $select = mysql_query('SELECT * FROM pages'); while ($return = mysql_fetch_assoc($select)) { $title = $return['title']; $author = $return['author']; $content = $return['content']; } then I can use these variables through out the page. Now, doing it the above way isn't an issue when I only have 3 columns in a database but what if I am dealing with a huge database with many more columns. I have a nagging feeling that the pros do it in some more efficient way where they maybe loop through the table they are selecting from to find all columns it has and associate them with variables automatically. Is that the case? or is the above how you guys do it too?

  Read the article

• set up way of getting mysite.$domain

  - by jose silva

  Hi I have several domains, only one website and one databse table for each domain. example: wbesite.us - data from USA goes to database table main_usa wbesite.co.uk - data form UK goes to database table main_uk Only have one database with name of the website. Having only one website structured, and having variables like $sql="select * from main_".$countrycode." where bla..bla..., and many other variables to catch the domain extension, and so on... Now, instead of having one full website for each domain, how can set a script and wher do I put it in order to detect the domain that the user uses. In my server root do I create something like website.$domain ? Something like website OLX but for different purposes. I hope I made myself clear. Thank you.

  Read the article

• Which is the best Linux C/C++ debugger (or front-end to gdb) to help teaching programming?

  - by omer.gimenez

  I teach a sort of "lite" C++ programming course to novices ("lite" meaning no pointers, no classes, just plain old C, plus references and STL string and vectors). Students have no previous experience in programming, so I believe that using an interactive debugger would help them understand program flow, variables, and recursion. The course is taught in Linux. Teaching them to use gdb is just overkill (they will not use nor understand most features). I just need something simple but easy to use: to see at which line the program is now, what is in the stack (local variables, previous calls, etc.). I look something similar to old Turbo Pascal or Turbo C++ Borland's debugger, or Visual Studio debugger. Thank you,

  Read the article

• Django admin add page, how to, autofill with latest data(0002)+1=0003

  - by kotchphile

  When adding a new data, can we automatically add a dynamic default data where the value is previous recorded data(0002)+1=0003

  Read the article

• Why do I get strange output from Perl using SQL?

  - by benjamin button

  Here is my Perl code: foreach my $line (@tmp_field_validation) { chomp $line; my ($cycle_code,$cycle_month,$cycle_year)= split /\s*\|\s*/, $line; $cycle_code=~ s/^\s*(.*)\s*$/$1/; $cycle_month=~ s/^\s*(.*)\s*$/$1/; $cycle_year=~ s/^\s*(.*)\s*$/$1/; print "$line\n"; print "$cycle_code|$cycle_month|$cycle_year"; } Here is the output: 1 10 2009 1 10 2009|| What's wrong over here? I expected the pipes to be between the variables. Why are the pipes getting printed after all the three variables?

  Read the article

• Java Thread - Synchronization issue

  - by Yatendra Goel

  From Sun's tutorial: Synchronized methods enable a simple strategy for preventing thread interference and memory consistency errors: if an object is visible to more than one thread, all reads or writes to that object's variables are done through synchronized methods. (An important exception: final fields, which cannot be modified after the object is constructed, can be safely read through non-synchronized methods, once the object is constructed) This strategy is effective, but can present problems with liveness, as we'll see later in this lesson. Q1. Is the above statements mean that if an object of a class is going to be shared among multiple threads, then all instance methods of that class (except getters of final fields) should be made synchronized, since instance methods process instance variables?

  Read the article

• Switching from C++ (with a lot of STL use) to C for interpreter building

  - by wndsr

  I'm switching from C++ to C because I'm rebuilding my toy interpreter. I was used to vectors for dynamic allocation of objects like tokens or instructions of my programs, stacks and mainly strings with all their aspects. Now, in C I'm not going to have all these anymore. I know that I will have to use a lot of memory management, too. I'm completely new to C, I only know the high-level easy-life data structures from the STL, how can I get started with strings and dynamic memory allocation?

  Read the article

• Is it a good idea to define a variable in a local block for a case of a switch statement?

  - by Paperflyer

  I have a rather long switch-case statement. Some of the cases are really short and trivial. A few are longer and need some variables that are never used anywhere else, like this: switch (action) { case kSimpleAction: // Do something simple break; case kComplexAction: { int specialVariable = 5; // Do something complex with specialVariable } break; } The alternative would be to declare that variable before going into the switch like this: int specialVariable = 5; switch (action) { case kSimpleAction: // Do something simple break; case kComplexAction: // Do something complex with specialVariable break; } This can get rather confusing since it is not clear to which case the variable belongs and it uses some unnecessary memory. However, I have never seen this usage anywhere else. Do you think it is a good idea to declare variables locally in a block for a single case?

  Read the article

• please help please

  - by davit-datuashvili

  http://stackoverflow.com/questions/2836934/how-to-compare-two-char-variables please show me a few steps how to start to write this code please

  Read the article

< Previous Page | 216 217 218 219 220 221 222 223 224 225 226 227  | Next Page >