Search Results

Search found 3076 results on 124 pages for 'beginner'.

Page 114/124 | < Previous Page | 110 111 112 113 114 115 116 117 118 119 120 121  | Next Page >

  • C Programming Logic Error?

    - by mbpluvr64
    The following code compiles fine, but does not allow the user to choose whether or not the program is to run again. After giving the user the answer, the program automatically terminates. I placed the main code in a "do while" loop to have the ability to convert more than one time if I wanted too. I have tried to run the program in the command line (Mac and Ubuntu machines) and within XCode with the exact same results. Any assistance would be greatly appreciated. C Beginner P.S. Compiling on MacBookPro running Snow Leopard. #include <stdio.h> #include <stdlib.h> int main(void) { char anotherIteration = 'Y'; do { const float Centimeter = 2.54f; float inches = 0.0f; float result = 0.0f; // user prompt printf("\nEnter inches: "); scanf("%f", &inches); if (inches < 0) { printf("\nTry again. Enter a positive number.\n"); break; } else { // calculate result result = inches * Centimeter; } printf("%0.2f inches is %0.2f centimeters.\n", inches, result); // flush input fflush(stdin); // user prompt printf("\nWould you like to run the program again? (Y/N): "); scanf("%c", &anotherIteration); if ((anotherIteration != 'Y') || (anotherIteration != 'N')) { printf("\nEnter a Y or a N."); break; } } while(toupper(anotherIteration == 'Y')); printf("Program terminated.\n"); return 0; }

    Read the article

  • Establishing persistent connection to a database in Java

    - by gmile
    I've ran through several examples over the web, and found that every single time I need something from the DB, I should write the following code: try { // Step 1: Load the JDBC driver. Class.forName("mysql_driver_name"); // Step 2: Establish the connection to the database. String url = "jdbc:string_to_mysql_server"; Connection conn = DriverManager.getConnection(url,"user1","password"); // fetch from the DB ... } catch (Exception e) { System.err.println("Got an exception! "); System.err.println(e.getMessage()); } It's very annoying to put up this code every time I want something from the DB, so the question is - is there a way to only once connect entirely all my app to the DB somehow at the very start point, avoiding copy-pasting mentioned code, and then be able to do everything I want with DB? I've quickly looked through NetBeans's Project menu, but didn't find any clue on how to configurate a persistent connection to a selected DB. If it's important, i'm writing a purely desktop app, i.e. using Java EE. Also, it's worth mentioning that I'm a kinda beginner in Java.

    Read the article

  • Sphinx - Python modules, classes and functions documentation

    - by user343934
    Hi everyone, I am trying to document my small project through sphinx which im recently trying to get familiar with. I read some tutorials and sphinx documentation but couldn't make it. Setup and configurations are ok! just have problems in using sphinx in a technical way. My table of content should look like this --- Overview .....Contents ----Configuration ....Contents ---- System Requirements .....Contents ---- How to use .....Contents ---- Modules ..... Index ......Display ----Help ......Content Moreover my focus is on Modules with docstrings. Details of Modules are Directory:- c:/wamp/www/project/ ----- Index.py >> Class HtmlTemplate: .... def header(): .... def body(): .... def form(): .... def header(): .... __init_main: ##inline function ----- display.py >> Class MainDisplay: .... def execute(): .... def display(): .... def tree(): .... __init_main: ##inline function My Documentation Directory:- c:/users/abc/Desktop/Documentation/doc/ --- _build --- _static --- _templates --- conf.py --- index.rst I have added Modules directory to the system environment and edited index.rst with following codes just to test Table of content. But i couldn't extract docstring directly Index.rst T-Alignment Documentation The documentation covers general overview of the application covering functionalities and requirements in details. To know how to use application its better to go through the documentation. .. _overview: Overview .. _System Requirement: System Requirement Seq-alignment tools can be used in varied systems base on whether all intermediary applications are available or not like in Windows, Mac, Linux and UNIX. But, it has been tested on the Windows working under a beta version. System Applications Server .. _Configuration:: Configuration Basic steps in configuration involves in following categories Environment variables Apache setting .. _Modules:: Modules How can i continue from here... Moreover, i am just a beginner to sphinx documentation tool I need your suggestions to brings my modules docstring to my documentation page Thanks

    Read the article

  • How to compile Open Flash Chart v.1?

    - by geehertush01
    Let me just say, that I'm a total beginner in anything related to flash. I would like to compile latest version of OFC1 (v.1.9.7). It can be downloaded here: link. Unfortunately no tutorial of how to do it can be found anywhere. I succeeded in compiling OFC2 (v.Lug-Wyrm-Charmer). I installed FlashDevelop, then I found .proj file in the OFC2 package, opened it in FlashDevelop and built the project. It worked fine (although I had to fix some code errors, but it was simple). Unfortunately there is no project file in OFC1 package. I tried to create a new project (Project-New Project-AS3 Project). It created .proj file and few folders (src,bin...). I deleted 'Main.as' from 'src' folder. Then I copied all files from 'actionscript' folder from OFC1 to 'src' project folder. I opened the project and set 'open-flash-char.as' as Document Class (right click on the file in the project tree and 'Set Document Class'). Then I tried to build the project, but got an syntax error with (in 'open-flash-char.as'): #include "prototype.drawCircle.as" #include "prototype.fillCircle.as" #include "String.prototype.replace.as" So I removed "#" signs. But then I got an error ...\ofc1\projtest4\src\open-flash-chart.as: Error: A file found in a source-path must have an externally visible definition. If a definition in the file is meant to be externally visible, please put the definition in a package. I have no idea of how to continue. Maybe I'm doing everything wrong, because OFC1 is written in AS2 (probably), not AS3. I don't know. So my question is: How to compile OFC v.1.9.7?

    Read the article

  • How to get a number closest to the average in c++?

    - by Alex Zielinski
    What I'm trying to achieve is to take the average of the numbers stored in the array and find the number which is closest to it. My code compiles, but has an error just after starting. I think it's something to do with the memory handling (I don't feel confident with pointers, etc. yet) Could some nice guy take a look at my code and tell me what's wrong with it? (don't be hard on me, I'm a beginner) #include <iostream> #include <cmath> using namespace std; double* aver(double* arr, size_t size, double& average); int main() { double arr[] = {1,2,3,4,5,7}; size_t size = sizeof(arr)/sizeof(arr[0]); double average = 0; double* p = aver(arr,size,average); cout << *p << " " << average << endl; } double* aver(double* arr, size_t size, double& average){ int i,j,sum; double* m = 0; int tmp[7]; for(i=0;i<size;i++) sum += arr[i]; average = sum/size; for(j=0;j<size;j++){ tmp[j] = arr[j] - average; if(abs(tmp[j])>*m) *m = tmp[j]; } return m; }

    Read the article

  • NSMutableDictionary isn't stick around long enough

    - by Sean Danzeiser
    Sorry, beginner here . . . So I create an NSMutableDictionary in my app delegate when the application launches, and then later pass it on to a view controller, as it contains options for the VC like a background image, a url I want to parse, etc. Anyway, i wrote a custom init method for the VC, initWithOptions, where I pass the dictionary on. I'm trying to use this dictionary later on in other methods - so I created a NSMutableDictionary property for my VC and am trying to store the passed options dictionary there. However, when I go to get the contents of that property in later methods, it returns null. If i access it from the init method, it works. heres some sample code: -(id)initWithOptions:(NSMutableDictionary *)options { self = [super init]; if (self) { // Custom initialization self.optionsDict = [[NSMutableDictionary alloc]initWithDictionary:options]; NSLog(@"dictionary in init method %@",self.optionsDict); that NSLog logs the contents of the dictionary, and it looks like its working. then later when I do this: - (void)viewDidLoad { SDJConnection *connection = [[SDJConnection alloc]init]; self.dataArray = [connection getEventInfoWithURL:[dict objectForKey:@"urlkey"]]; NSLog(@"dictionary in connection contains: %@", [dict objectForKey:@"urlkey"]); [_tableView reloadData]; the dictionary returns null. Ive tried adjusting the property attributes, and it didn't work with either strong or retain. Any ideas?? THANKS!!

    Read the article

  • I have a problem with a4j:commandButton and a reredering ...

    - by ollie314
    The code below show whiche thing that is failing in my appliaction. It is a quick add information form, fill out the form and submit it add a new entry into a database and synchronize my a databasle.. This is all done with ajax. The first form submission happens correctly but the second one fails to run the desired ActionListener. The second form is posting to the server though but the saveAction isn't invoke. As you will see, I'm a real beginner with this technologies ... If someone see the problem, it will be very helpfull !! <rich:simpleTogglePanel id="quickaddActivitySimpleToogle" switchType="client" opened="false" label="#{lang.activityModule_quickAdd_panelTitle}"> <p><a4j:form id="quickAddForm"> <h:outputLabel for="activityNameInput" value="#{lang.activity_name_dp}" /> <h:inputText id="activityNameInput" value="#{activityController.quickActivityAdd.name}"> </h:inputText> <rich:spacer width="20px" /> <h:inputHidden id="activityInternalNameInput" value="#{activityController.quickActivityAdd.internalName}" /> <rich:spacer width="20px" /> <a4j:commandButton id="activityQuickAddFormSubmitBtn" reRender="activityListTable,quickAddForm" actionListener="#{activityController.saveActivity}" value="#{lang.saveBtn_header}" /> </a4j:form></p></rich:simpleTogglePanel> Thanks in advanced. ollie314

    Read the article

  • PHP: Need help with simple XML

    - by Jack
    I am beginner in PHP. I am trying to parse this xml file. <relationship> <target> <following type="boolean">true</following> <followed_by type="boolean">true</followed_by> <screen_name>xxxx</screen_name> <id type="integer">xxxx</id> </target> <source> <notifications_enabled nil="true"/> <following type="boolean">true</following> <blocking nil="true"/> <followed_by type="boolean">true</followed_by> <screen_name>xxxx</screen_name> <id type="integer">xxxxx</id> </source> </relationship> I need to get the value of the field 'following type="boolean" ' for the target and here's my code - $xml = simplexml_load_string($response); foreach($xml->children() as $child) { if ($child->getName() == 'target') { foreach($child->children() as $child_1) if ( $child_1->getName() == 'following') { $is_my_friend = (bool)$child_1; break; } break; } } but I am not getting the correct output. I think the ' type="boolean" ' part of the field is creating problems. Please help.

    Read the article

  • Yet another Haskell vs. Scala question

    - by Travis Brown
    I've been using Haskell for several months, and I love it—it's gradually become my tool of choice for everything from one-off file renaming scripts to larger XML processing programs. I'm definitely still a beginner, but I'm starting to feel comfortable with the language and the basics of the theory behind it. I'm a lowly graduate student in the humanities, so I'm not under a lot of institutional or administrative pressure to use specific tools for my work. It would be convenient for me in many ways, however, to switch to Scala (or Clojure). Most of the NLP and machine learning libraries that I work with on a daily basis (and that I've written in the past) are Java-based, and the primary project I'm working for uses a Java application server. I've been mostly disappointed by my initial interactions with Scala. Many aspects of the syntax (partial application, for example) still feel clunky to me compared to Haskell, and I miss libraries like Parsec and HXT and QuickCheck. I'm familiar with the advantages of the JVM platform, so practical questions like this one don't really help me. What I'm looking for is a motivational argument for moving to Scala. What does it do (that Haskell doesn't) that's really cool? What makes it fun or challenging or life-changing? Why should I get excited about writing it?

    Read the article

  • return an ArrayList method

    - by Bopeng Liu
    This is a drive method for two other classes. which i posted here http://codereview.stackexchange.com/questions/33148/book-program-with-arraylist I need some help for the private static ArrayList getAuthors(String authors) method. I am kind a beginner. so please help me finish this drive method. or give me some directions. Instruction some of the elements of the allAuthors array contain asterisks “*” between two authors names. The getAuthors method uses this asterisk as a delimiter between names to store them separately in the returned ArrayList of Strings. import java.util.ArrayList; public class LibraryDrive { public static void main(String[] args) { String[] titles = { "The Hobbit", "Acer Dumpling", "A Christmas Carol", "Marley and Me", "Building Java Programs", "Java, How to Program" }; String[] allAuthors = { "Tolkien, J.R.", "Doofus, Robert", "Dickens, Charles", "Remember, SomeoneIdont", "Reges, Stuart*Stepp, Marty", "Deitel, Paul*Deitel, Harvery" }; ArrayList<String> authors = new ArrayList<String>(); ArrayList<Book> books = new ArrayList<Book>(); for (int i = 0; i < titles.length; i++) { authors = getAuthors(allAuthors[i]); Book b = new Book(titles[i], authors); books.add(b); authors.remove(0); } Library lib = new Library(books); System.out.println(lib); lib.sort(); System.out.println(lib); } private static ArrayList<String> getAuthors(String authors) { ArrayList books = new ArrayList<String>(); // need help here. return books; } }

    Read the article

  • Help regarding Android NDK

    - by Siva Kumar
    I am a beginner in using Android NDK. I am using Eclipse and I installed cygwin to build the c file to generate the .so file But while building the c file in cygwin I am always getting the error make: ***No rule to make target 'file.c' ... .Stop I tried building different C codes but for every file it says the same error .. Here is the source code: public class ndktest extends Activity { static { System.loadLibrary("ndkt"); } private native void helloLog(String logThis); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); helloLog("this is to test log file"); } } file.c void Java_com_ndktest_helloLog(JNIEnv * env, jobject this, jstring logThis) { jboolean isCopy; const char * szLogThis = (*env)->GetStringUTFChars(env, logThis, &isCopy); (*env)->ReleaseStringUTFChars(env, logThis, szLogThis); } And here is my Android.mk LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_LDLIBS := -llog LOCAL_MODULE := ndkt LOCAL_SRC_FILES := file.c include $(BUILD_SHARED_LIBRARY) I searched for the solution for the cause of error ... but nothing works for me. Can anyone tell me where I am making the mistake ? Thanks, Siva Kumar

    Read the article

  • Using ScriptingBridge framework for communicating with Entourage

    - by Subramanian Ganapathy
    Hi, The motivation for my question is the following doc, which describes how mail.app could be integrated using ScriptingBridge: http://developer.apple.com/mac/library/samplecode/SBSendEmail/Introduction/Intro.html I tried to apply a similar technique with Entourage as well but could not get any results so far. I understand that using AppleScript would help me solve my problem and mactech.com has extensive documentation for doing so. But i find this ScriptingBridge technique elegant and want to figure why it is not working for me with Entourage. The biggest problem seems to be my inability to create Scripting classes based on their names as it happens in Mail because Entourage has a different interface than Mail as their headers indicate. Could someone please tell me what I am missing or provide any sort of hint on why this wont work? I am also adding sample code ` MicrosoftEntourageApplication * mail = [SBApplication applicationWithBundleIdentifier:@"com.Microsoft.Entourage"]; MicrosoftEntourageOutgoingEmailMessage * emailMessage = [[[mail classForScriptingClass:@"outgoing message"] alloc] initWithProperties: [NSDictionary dictionaryWithObjectsAndKeys: @"my sample subject", @"subject", @"my sample body", @"content", nil]]; //then i create a set of recipients and try to use "to recipient" as the string scripting class id, but MicrosoftEntourageRecipient is returned as nil MicrosoftEntourageRecipient * theRecipient = [[[mail classForScriptingClass:@"to recipient"] alloc] initWithProperties: [NSDictionary dictionaryWithObjectsAndKeys: @"[email protected]", @"address", nil]]; ` I am trying to make the simple thing work, I am not even concentrating on the task I am supposed to do now. I am a Cocoa beginner( and willing to learn ), please excuse an syntactic naivetes and do point them out in the sample code, in addition to answering my question. Best Regards, Subramanian

    Read the article

  • Zend framework controller action helper

    - by guptanikhilchandra
    I am getting fatal error after adding the action helper class. I am trying to load layout corresponding to called layout. Following is my code snippet: First of all i added a helper class under application/controller/helpers: class Zend_Controller_Action_Helper_Layout extends Zend_Controller_Action_Helper_Abstract { public $pluginLoader; public function __construct() { // TODO Auto-generated Constructor $this->pluginLoader = new Zend_Loader_PluginLoader (); } public function preDispatch() { $bootstrap = $this->getActionController()->getInvokeArg('bootstrap'); $config = $bootstrap->getOptions(); $module = $this->getRequest()->getModuleName(); if (isset($config[$module]['resources']['layout']['layout'])) { $layoutScript = $config[$module]['resources']['layout']['layout']; $this->getActionController()->getHelper('layout')->setLayout($layoutScript); } } } Then i added a loader in bootstrap.php: protected function _initLayoutHelper() { $this->bootstrap('frontController'); Zend_Controller_Action_HelperBroker::addPath(APPLICATION_PATH .'/controllers/helpers'); $layout = Zend_Controller_Action_HelperBroker::addHelper(new Zend_Controller_Action_Helper_Layout()); } Following is my application.ini: [production] autoloaderNamespaces.tree = "Tree_" phpSettings.display_startup_errors = 0 phpSettings.display_errors = 0 includePaths.library = APPLICATION_PATH "/../library" bootstrap.path = APPLICATION_PATH "/Bootstrap.php" bootstrap.class = "Bootstrap" resources.frontController.controllerDirectory = APPLICATION_PATH "/controllers" resources.frontController.moduleDirectory = APPLICATION_PATH "/modules" resources.frontController.helperDirectory = APPLICATION_PATH "/controllers/helpers" resources.modules[] = "" contact.resources.frontController.defaultControllerName = "index" resources.layout.layoutPath = APPLICATION_PATH "/layouts/scripts" resources.layout.layout = layout admin.resources.layout.layout = admin admin.resources.layout.layoutPath = APPLICATION_PATH "/layouts/scripts" resources.view[] = [staging : production] [testing : production] phpSettings.display_startup_errors = 1 phpSettings.display_errors = 1 [development : production] phpSettings.display_startup_errors = 1 phpSettings.display_errors = 1 While running this code i am getting following errors: Warning: include(Zend\Controller\Action\Helper\LayoutLoader.php) [function.include]: failed to open stream: No such file or directory in D:\personal\proj\renovate\library\Zend\Loader.php on line 83 Warning: include() [function.include]: Failed opening 'Zend\Controller\Action\Helper\LayoutLoader.php' for inclusion (include_path='D:\personal\proj\renovate\application/../library;D:\personal\proj\renovate\library;.;C:\php5\pear') in D:\personal\proj\renovate\library\Zend\Loader.php on line 83 Fatal error: Class 'Zend_Controller_Action_Helper_LayoutLoader' not found in D:\personal\proj\renovate\application\Bootstrap.php on line 33 Kindly let me know, how can i come out from this issue. I am beginner in Zend Framework. Thanks Nikhil

    Read the article

  • WPF : Access Application Resources when not referencing Shell from App.xaml

    - by CF_Maintainer
    I am beginner in WPF. My App.xaml looks like below app.xaml <Application x:Class="ContactManager.App" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> <Application.Resources> <Color x:Key="lightBlueColor">#FF145E9D</Color> <SolidColorBrush x:Key="lightBlueBrush" Color="{StaticResource lightBlueColor}" /> </Application.Resources> I do not set the startupuri since I want to a presenter first approach. I do the following in app.xaml.cs protected override void OnStartup(StartupEventArgs e) { base.OnStartup(e); var appPresenter = new ApplicationPresenter( new Shell(), new ContactRepository()); appPresenter.LaunchView(); } I have a usercontrol called "SearchBar.xaml" which references "lightBlueBrush" as a staticResource. When I try to open "Shell.xaml" in the designer it tells me : The "shell.xaml" cannot be loaded at design time because it says it could not create an instance of type "SearchBar.xaml". When I debugged the devenv.exe using another visual studio instance it tells me that it does not have access to the Brush I created in app.resources. If one is doing a Presenter first approach, how does one access resources? I had this working when the startupURI was "Shell.xaml" and the startup event was not present. Any clues/ideas/suggestions. I am just trying to understand. Everything works as expected when I run the application just not @ design time.

    Read the article

  • python: help defining/installing simple script to setup machine-specific information

    - by Jason S
    (This is related to scons but I think most of the following should be fairly general to python) I would like to define a python file/library that I put in a Well-Known Place somewhere on my computer that I can use to define machine-specific paths, and was looking for help on how to do this well, since I'm a beginner to Python & really only use it for my scons work. scons uses a SConstruct file which can execute python code. What I would like to do is something like this: My SConstruct file would contain this at the beginning: defaultEnv = JJJJJ.getMachineSpecificPaths() or (do both of these syntaxes work?) import JJJJJ defaultEnv = getMachineSpecificPaths() I define a JJJJJ.py file somewhere installed in the python dir which contains the following def getMachineSpecificPaths(): ... does something here, I don't know what ... that reads a file machine-specific-paths.txt (maybe it has the code Ross Rogers mentioned in my other question) located in the same directory as JJJJJ.py containing the following: machine-specific-paths.txt TI_C28_ROOT C:/appl/ti/ccs/?4.1.1/ccsv4/tools/co?mpiler/c2000 JSDB c:/bin/jsdb/jsdb.exe PYTHON_PATH c:/appl/python/2.6.4 The thing is, I don't really know much about the conventions in Python about where you put system-wide libraries and files. This is probably really simple to get right but I don't know how.

    Read the article

  • Database nesting layout confusion

    - by arzon
    I'm no expert in databases and a beginner in Rails, so here goes something which kinda confuses me... Assuming I have three classes as a sample (note that no effort has been made to address any possible Rails reserved words issue in the sample). class File < ActiveRecord::Base has_many :records, :dependent => :destroy accepts_nested_attributes_for :records, :allow_destroy => true end class Record < ActiveRecord::Base belongs_to :file has_many :users, :dependent => :destroy accepts_nested_attributes_for :users, :allow_destroy => true end class User < ActiveRecord::Base belongs_to :record end Upon entering records, the database contents will appear as such. My issue is that if there are a lot of Files for the same Record, there will be duplicate record names. This will also be true if there will be multiple Records for the same user in the the Users table. I was wondering if there is a better way than this so as to have one or more files point to a single Record entry and one or more Records will point to a single User. BTW, the File names are unique. Files table: id name 1 name1 2 name2 3 name3 4 name4 Records table: id file_id record_name record_type 1 1 ForDaisy1 ... 2 2 ForDonald1 ... 3 3 ForDonald2 ... 4 4 ForDaisy1 ... Users table: id record_id username 1 1 Daisy 2 2 Donald 3 3 Donald 4 4 Daisy Is there any way to optimize the database to prevent duplication of entries, or this should really the correct and proper behavior. I spread out the database into different tables to be able to easily add new columns in the future.

    Read the article

  • Loading page all content and scripts inside another

    - by Robin I Knight
    If you go to this page on our website: http://www.divethegap.com/scuba-diving-programmes-dive-the-gap/dahab-divemaster-training.html The buttons at the bottom that say 'Beginner' 'Open Water Diver' etc.... They take you to another page where you have a series of options and can book. We would like it so that rather than have to navigate to another page it loaded those options and all the scripts that make the calculations in a div on the first page. Depending on which button you press depends on which page it would load inside the div. IFrame does not work as it does not dynamically resize when the collapsible panels are opened. AJAX script at dynamic drive. http://www.dynamicdrive.com/dynamicindex17/ajaxcontent.htm does not work as none of the collapsible panels work, nor does the calculation script. How can this be done. To sum it up it would be like turning the buttons at the bottom of the page into tabs that would display the content from the pages those buttons currently link through to. Is this possible.

    Read the article

  • Changing variables outside of Scope C#

    - by sam
    Hi, I'm a beginner C# programmer, and to improve my skills I decided to give Project Euler a try. The first problem on the site asks you to find the sum of all the multiples of 3 and 5 under 1000. Since I'm essentially doing the same thing twice, I made a method to multiply a base number incrementally, and add the sum of all the answers togethor. public static int SumOfMultiplication(int Base, int limit) { bool Escape = false; for (int mult = 1; Escape == true; mult++) { int Number = 0; int iSum = 0; Number = Base * mult; if (Number > limit) return iSum; else iSum = iSum + Number; } regardless of what I put in for both parameters, it ALWAYS returns zero. I'm 99% sure it has something to do with the scope of the variables, but I have no clue how to fix it. All help is appreciated. Thanks in advance, Sam

    Read the article

  • finding ALL cycles in a huge sparse matrix

    - by Andy
    Hi there, First of all I'm quite a Java beginner, so I'm not sure if this is even possible! Basically I have a huge (3+million) data source of relational data (i.e. A is friends with B+C+D, B is friends with D+G+Z (but not A - i.e. unmutual) etc.) and I want to find every cycle within this (not necessarily connected) directed graph. I've found this thread (http://stackoverflow.com/questions/546655/finding-all-cycles-in-graph/549402#549402) which has pointed me to Donald Johnson's (elementary) cycle-finding algorithm which, superficially at least, looks like it'll do what I'm after (I'm going to try when I'm back at work on Tuesday - thought it wouldn't hurt to ask in the meanwhile!). I had a quick scan through the code of the Java implementation of Johnson's algorithm (in that thread) and it looks like a matrix of relations is the first step, so I guess my questions are: a) Is Java capable of handling a 3+million*3+million matrix? (was planning on representing A-friends-with-B by a binary sparse matrix) b) Do I need to find every connected subgraph as my first problem, or will cycle-finding algorithms handle disjoint data? c) Is this actually an appropriate solution for the problem? My understanding of "elementary" cycles is that in the graph below, rather than picking out A-B-C-D-E-F it'll pick out A-B-F, B-C-D etc. but that's not the end of the world given the task. E / \ D---F / \ / \ C---B---A d) If necessary, I can simplify the problem by enforcing mutuality in relations - i.e. A-friends-with-B <== B-friends-with-A, and if really necessary I can maybe cut down the data size, but realistically it is always going to be around the 1mil mark. z) Is this a P or NP task?! Am I biting off more than I can chew? Thanks all, any help appreciated! Andy

    Read the article

  • Is a GWT app running on Google App Engine protected from CSRF

    - by gerdemb
    I'm developing a GWT app running on the Google App Engine and wondering if I need to worry about Cross-site request forgery or is that automatically taken care of for me? For every RPC request that requires authentication, I have the following code: public class BookServiceImpl extends RemoteServiceServlet implements BookService { public void deleteInventory(Key<Inventory> inventoryKey) throws NotLoggedInException, InvalidStateException, NotFoundException { DAO dao = new DAO(); // This will throw NotLoggedInException if user is not logged in User user = dao.getCurrentUser(); // Do deletion here } } public final class DAO extends DAOBase { public User getCurrentUser() throws NotLoggedInException { currentUser = UserServiceFactory.getUserService().getCurrentUser(); if(currentUser == null) { throw new NotLoggedInException(); } return currentUser; } I couldn't find any documentation on how the UserService checks authentication. Is it enough to rely on the code above or do I need to to more? I'm a beginner at this, but from what I understand to avoid CSRF attacks some of the strategies are: adding an authentication token in the request payload instead of just checking a cookie checking the HTTP Referer header I can see that I have cookies set from Google with what look like SID values, but I can't tell from the serialized Java objects in the payloads if tokens are being passed or not. I also don't know if the Referer header is being used or not. So, am I worrying about a non-issue? If not, what is the best strategy here? This is a common enough problem, that there must be standard solutions out there...

    Read the article

  • php fopen function dies, though I have file permissions set to read and write

    - by Matthew Robert Keable
    I'm following a tutorial on php, and am having difficulty getting this to work. I set the appropriate directory permissions to read and write, but every time I run this, I get the die string. The code is: $ourFileName = "testFile.txt"; $ourFileHandle = fopen($ourFileName, 'w') or die("can't open file"); fclose($ourFileHandle); As far as my basic understanding goes, if "testFile.txt" does not exist, fopen should create that file (I have basic knowledge of Python, and remember this same principle in that language). But it...it doesn't. Even if I create the aforementioned file, and put it up, that line of code still returns a die string. My hosting account does not give me permission to execute. Is this a problem? My server runs on Windows. I am using Dreamweaver CS5, on OSX 10.5.8. I've done some searching on this, and see other people having similar issues - but none of them keyed to exactly my range of problems. Being that I'm a beginner, I feel that it might be something I'm overlooking. Thanks!!

    Read the article

  • How to define a "complicated" ComputedColumn in SQL Server?

    - by Slauma
    SQL Server Beginner question: I'm trying to introduce a computed column in SQL Server (2008). In the table designer of SQL Server Management Studio I can do this, but the designer only offers me one single edit cell to define the expression for this column. Since my computed column will be rather complicated (depending on several database fields and with some case differentiations) I'd like to have a more comfortable and maintainable way to enter the column definition (including line breaks for formatting and so on). I've seen there is an option to define functions in SQL Server (scalar value or table value functions). Is it perhaps better to define such a function and use this function as the column specification? And what kind of function (scalar value, table value)? To make a simplified example: I have two database columns: DateTime1 (smalldatetime, NULL) DateTime2 (smalldatetime, NULL) Now I want to define a computed column "Status" which can have four possible values. In Dummy language: if (DateTime1 IS NULL and DateTime2 IS NULL) set Status = 0 else if (DateTime1 IS NULL and DateTime2 IS NOT NULL) set Status = 1 else if (DateTime1 IS NOT NULL and DateTime2 IS NULL) set Status = 2 else set Status = 3 Ideally I would like to have a function GetStatus() which can access the different column values of the table row which I want to compute the value of "Status" for, and then only define the computed column specification as GetStatus() without parameters. Is that possible at all? Or what is the best way to work with "complicated" computed column definitions? Thank you for tips in advance!

    Read the article

  • How to compare two variables from a java class in jess and execute a rule?

    - by user3417084
    I'm beginner in Jess. I'm trying to compare two variables from a Java class in Jess and trying to execute a rule. I have imported cTNumber and measuredCurrent (both are integer)form a java class called CurrentSignal. Similarly imported vTNumberand measuredVoltage form a java class DERSignal. Now I want to make a rule such that if cTNumber is equal to vTNumber then multiply measuredCurrent and measuredVoltage (Both are double) for calculating power. I'm trying in this way.... (import signals.*) (deftemplate CurrentSignal (declare (from-class CurrentSignal))) (deftemplate DERSignal (declare (from-class DERSignal))) (defglobal ?*CTnumber* = 0) (defglobal ?*VTnumber* = 0) (defglobal ?*VTnumberDER* = 0) (defglobal ?*measuredCurrent* = 0) (defglobal ?*measuredVoltage* = 0) (defglobal ?*measuredVoltageDER* = 0) (defrule Get-CT-Number (CurrentSignal (cTNumber ?m)) (CurrentSignal (measuredCurrent ?c)) => (bind ?*measuredCurrent* ?c) (printout t "Measured Current : " ?*measuredCurrent*" Amps"crlf) (bind ?*CTnumber* ?m) (printout t ?*CTnumber* crlf) ) (defrule Get-DER-Number (DERSignal (vTNumber ?o)) (DERSignal (measuredVoltage ?V)) => (bind ?*measuredVoltageDER* ?V) (printout t "Measured Voltage : " ?*measuredVoltageDER* " V" crlf) (bind ?*VTnumberDER* ?o) (printout t ?*VTnumberDER* crlf) ) (defrule Power-Calculation-DER-signal "Power calculation of DER Bay" (test (= ?*CTnumber* ?*VTnumberDER* )) => (printout t "Total Generation : " (* ?*measuredCurrent* ?*measuredVoltageDER*) crlf) ) But the Total Generation is showing 0. But I tried calculating in Java and it's showing a number. Can anyone please help me to solve this problem. Thank you.

    Read the article

  • Python virtualenv questions

    - by orokusaki
    I'm using VirtualEnv on Windows XP. I'm wondering if I have my brain wrapped around it correctly. I ran virtualenv ENV and it created C:\WINDOWS\system32\ENV. I then changed my PATH variable to include C:\WINDOWS\system32\ENV\Scripts instead of C:\Python27\Scripts. Then, I checked out Django into C:\WINDOWS\system32\ENV\Lib\site-packages\django-trunk, updated my PYTHON_PATH variable to point the new Django directory, and continued to easy_install other things (which of course go into my new C:\WINDOWS\system32\ENV\Lib\site-packages directory). I understand why I should use VirtualEnv so I can run multiple versions of Django, and other libraries on the same machine, but does this mean that to switch between environments I have to basically change my PATH and PYTHON_PATH variable? So, I go from developing one Django project which uses Django 1.2 in an environment called ENV and then change my PATH and such so that I can use an environment called ENV2 which has the dev version of Django? Is that basically it, or is there some better way to automatically do all this (I could update my path in Python code, but that would require me to write machine-specific code in my application)? Also, how does this process compare to using VirtualEnv on Linux (I'm quite the beginner at Linux).

    Read the article

  • OOP - Handling Automated Instances of a Class - PHP

    - by dscher
    This is a topic that, as a beginner to PHP and programming, sort of perplexes me. I'm building a stockmarket website and want users to add their own stocks. I can clearly see the benefit of having each stock be a class instance with all the methods of a class. What I am stumped on is the best way to give that instance a name when I instantiate it. If I have: class Stock() { ....doing stuff..... } what is the best way to give my instances of it a name. Obviously I can write: $newStock = new Stock(); $newStock.getPrice(); or whatever, but if a user adds a stock via the app, where can the name of that instance come from? I guess that there is little harm in always creating a new child with $newStock = new Stock() and then storing that to the DB which leads me to my next question! What would be the best way to retrieve 20 user stocks(for example) into instances of class Stock()? Do I need to instantiate 20 new instances of class Stock() every time the user logs in or is there something I'm missing? I hope someone answers this and more important hope a bunch of people answer this and it somehow helps someone else who is having a hard time wrapping their head around what probably leads to a really elegant solution. Thanks guys!

    Read the article

< Previous Page | 110 111 112 113 114 115 116 117 118 119 120 121  | Next Page >