Search Results

Search found 68254 results on 2731 pages for 'open question'.

Page 99/2731 | < Previous Page | 95 96 97 98 99 100 101 102 103 104 105 106  | Next Page >

• Apress Deal of the Day - 5Mar/2011 - Crafting Digital Media: Audacity, Blender, Drupal, GIMP, Scribus, and other Open Source Tools

  - by TATWORTH

  Today's Apress $10 deal of the day at http://www.apress.com/info/dailydeal has been on before. I have a copy and it is useful read on open source applications for Windows. Crafting Digital Media: Audacity, Blender, Drupal, GIMP, Scribus, and other Open Source Tools Open source software, also known as free software, now offers a creative platform with world-class programs. Crafting Digital Media is your foundation course in photographic manipulation, illustration, animation, making music, video editing, and more using open source software.

  Read the article

• BonitaSoft lauréat des OW2 Best Project Awards, un prix qui clôture une année 2012 excellente pour le BPM open-source français

  BonitaSoft lauréat des OW2 Best Project Awards 2012 Un prix qui clôture une année 2012 excellente pour le BPM open-source français OW2, la communauté internationale pour le middleware et les plates-formes applicatives open source, a annoncé les résultats de ses premiers OW2 Best Project Awards. Parmi les quatre projets open source innovants primés cette année, on retrouve dans la catégorie « Market » le BPM français Bonita Open Solution. Un prix qui vient clôturer une année pleine de succès pour l'éditeur français (lire par ailleurs « BonitaSoft dépasse le million et demi de téléchargements »).

  Read the article

• GIMP abandonne la plateforme d'hébergement SourceForge, la forge open source critiquée pour inclure des adwares dans les téléchargements

  GIMP abandonne la plateforme d'hébergement SourceForge la forge open source critiquée pour inclure des adwares dans les téléchargementsSourceForge, l'une des plateformes populaires d'hébergement des projets libres et open source perd de plus en plus de crédibilité auprès des communautés open source. Pour cause : les nouvelles directives de SourceForge, qui incitent le téléchargement de nombreux logiciels non désirés par l'utilisateur.GIMP, le célèbre logiciel open source, alternatif à Photoshop,...

  Read the article

• General Question About WPF Control Behavior and using Invoke

  - by Phil Sandler

  I have been putting off activity on SO because my current reputation is "1337". :) This is a question of "why" and not "how". By default, it seems that WPF does not set focus to the first control in a window when it's opening. In addition, when a textbox gets focus, by default it does not have it's existing text selected. So basically when I open a window, I want focus on the first control of the window, and if that control is a textbox, I want it's existing text (if any) to be selected. I found some tips online to accomplish each of these behaviors, and combined them. The code below, which I placed in the constructor of my window, is what I came up with: Loaded += (sender, e) => { MoveFocus(new TraversalRequest(FocusNavigationDirection.Next)); var textBox = FocusManager.GetFocusedElement(this) as TextBox; if (textBox != null) { Action select = textBox.SelectAll; //for some reason this doesn't work without using invoke. Dispatcher.Invoke(DispatcherPriority.Loaded, select); } }; So, my question. Why does the above not work without using Dispatcher.Invoke? Is something built into the behavior of the window (or textbox) cause the selected text to be de-selected post-loading? Maybe related, maybe not--another example of where I had to use Dispatcher.Invoke to control the behavior of a form: http://stackoverflow.com/questions/2602979/wpf-focus-in-tab-control-content-when-new-tab-is-created

  Read the article

• Beginner question - Loop invariants (Specifically Ch.3 of "Accelerated C++")

  - by Owen

  Hi - as I said, a complete beginner question here. I'm currently working my way through "Accelerated C++" and just came across this in chapter 3: // invariant: // we have read count grades so far, and // sum is the sum of the first count grades while (cin >> x) { ++count; sum += x; } The authors follow this by explaining that the invariant needs special attention paid to it because when the input is read into the variable x, we will have read count+1 grades and thus the invariant will be untrue. Similarly, when we have incremented the counter, the variable sum will no longer be the sum of the last count grades (in case you hadn't guessed, it's the traditional program for calculating student marks). What I don't understand is why this matters. Surely for just about any other loop, a similar statement would be true? For example, here is the book's first while loop (the output is filled in later): // invariant: we have written r rows so far while (r != rows) { // write a row of output std::cout << std::endl; ++r; } Once we have written the appropriate row of output, surely the invariant is false until we have incremented r, just as in the other example? It's probably something really obvious, anyone could enlighten me as to what makes these two cases different, that'd be great - and thanks in advance for taking the time to answer such a complete novice question. Owen

  Read the article

• rails question find no result

  - by Small Wolf

  Hey.Guys! Now .I have a question ,i want someone to help me to solve it ,the log of the problem like the under text >> Department.find(EmeReference.find(:all,:select =>:ref_config_id,:conditions=>"emergency_id = 1")) ActiveRecord::RecordNotFound: Couldn't find Department with ID=0 from /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:1591:in `find_one' from /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:1574:in `find_from_ids_without_cache' from (__DELEGATION__):2:in `__send__' from (__DELEGATION__):2:in `find_from_ids_without_cache' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/query/abstract.rb:158:in `find_from_keys' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/query/primary_key.rb:31:in `miss' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/query/abstract.rb:66:in `hit_or_miss' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/accessor.rb:17:in `call' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/accessor.rb:17:in `fetch' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/accessor.rb:29:in `get' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/query/abstract.rb:65:in `hit_or_miss' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/query/abstract.rb:18:in `perform' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/query/primary_key.rb:17:in `perform' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/query/abstract.rb:7:in `perform' from /usr/lib/ruby/gems/1.8/gems/nkallen-cache-money-0.2.5/lib/cash/finders.rb:29:in `find_from_ids' from /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:616:in `find' from (irb):135 that's the question! Thank your and best regards!

  Read the article

• Maths Question: number of different permutations

  - by KingCong

  This is more of a maths question than programming but I figure a lot of people here are pretty good at maths! :) My question is: Given a 9 x 9 grid (81 cells) that must contain the numbers 1 to 9 each exactly 9 times, how many different grids can be produced. The order of the numbers doesn't matter, for example the first row could contain nine 1's etc. This is related to Sudoku and we know the number of valid Sudoku grids is 6.67×10^21, so since my problem isn't constrained like Sudoku by having to have each of the 9 numbers in each row, column and box then the answer should be greater than 6.67×10^21. My first thought was that the answer is 81! however on further reflection this assume that the 81 number possible for each cell are different, distinct number. They are not, there are 81 possible numbers for each cell but only 9 possible different numbers. My next thought was then that each of the cells in the first row can be any number between 1 and 9. If by chance the first row happened to be all the same number, say all 1s, then each cell in the second row could only have 8 possibilites, 2-9. If this continued down until the last row then number of different permutations could be calculated by 9^2 * 8^2 * 7^2 ..... * 1^2. However this doesn't work if each row doesn't contain 9 of the same number. It's been quite a while since I studied this stuff and I can't think of a way to work it out, I'd appreciate any help anyone can offer.

  Read the article

• How to handle EntityExistsException properly?

  - by Ivan Yatskevich

  I have two entities: Question and FavoritesCounter. FavoritesCounter should be created when the question is added to favorites for the first time. Consider a use case when two users tries to add a question to favorites simultaneously - this will cause EntityExistsException when entityManager.persist(counter) is called for the second user. But the code below doesn't work, because when EntityExistsException is thrown, container marks transaction as rollback only and attempt to return getFavoritesCounter(question) fails with javax.resource.ResourceException: Transaction is not active @Stateless public class FavoritesServiceBean implements FavoritesService { ... public void addToFavorites(Question question) { FavoritesCounter counter = getCounter(question); if (counter == null) { counter = createCounter(question); } //increase counter } private FavoritesCounter createCounter(Question question) { try { FavoritesCounter counter = new FavoritesCounter(); counter.setQuestion(question); entityManager.persist(counter); entityManager.flush(); return counter; } catch (EntityExistsException e) { return getFavoritesCounter(question); } } private FavoritesCounter getFavoritesCounter(Question question) { Query counterQuery = entityManager.createQery("SELECT counter FROM FavoritesCounter counter WHERE counter.question = :question"); counterQuery.setParameter("question", question); List<FavoritesCounter> result = counterQuery.getResultList(); if (result.isEmpty()) return null; return result.get(0); } } Question @Entity public class Question implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } FavoritesCounter @Entity public class FavoritesCounter implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @OneToOne @Column(unique = true) private Question question; //getter and setter } What is the best way to handle such a situation - return already created entity after EntityExistsException?

  Read the article

• Sharepoint survey: How to identify the question fields when fetching survey information from the Lis

  - by paul

  I am wanting to access survey information via the Lists web service and display the questions contained in the survey. The result contains a large number of Field nodes some of which are the questions in the survey. The other fields contain other information such as author, last changed etc. How can I pick out the questions? I had thought that all non-questions would be hidden but this is not the case. Here is my code as it is at the moment. It returns about 16 items. The survey has 6 questions... // read question definitions string[] HandleTypes = new string[] { "Number", "DateTime", "Text", "Choice", "GridChoice", "Boolean" }; var query = from n in node.Descendants(ns+"Field") where (n.Attribute("Hidden") == null || n.Attribute("Hidden").Value.ToLower() == "true") && (n.Attribute("Type") != null && HandleTypes.Contains(n.Attribute("Type").Value)) select new Question(n.Attribute("ID").Value) { Text = n.Attribute("DisplayName").Value, QuestionType = n.Attribute("Type").Value, Element = n }; Ideas anyone?

  Read the article

• Authlogic Current User Question - hiding admin links...

  - by bgadoci

  I think I am missing something while using the Authlogic gem w/ Rails. To set the stage I have multiple users and each user can create posts and comments. Upon the display of a post or comment I would like to give the user who created them the option to edit or destroy. I am successfully using the following code to hide and show elements based on if a user is logged in or not but can't seem to find out how to only show these links to the actual user who created them...not any user that is logged in. <% if current_user %> <%= link_to 'Edit', edit_question_path(question) %> | <%= link_to 'Destroy', question, :confirm => 'Are you sure?', :method => :delete %> <% else %> <p>nothing to see here</p> <% end %> Here is the def of current_user located in the application controller in case I need to change something here. class ApplicationController < ActionController::Base helper :all # include all helpers, all the time protect_from_forgery # See ActionController::RequestForgeryProtection for details# helper_method :current_user private def current_user_session return @current_user_session if defined?(@current_user_session) @current_user_session = UserSession.find end def current_user return @current_user if defined?(@current_user) @current_user = current_user_session && current_user_session.record end end

  Read the article

• Unicode strings in my C# App are shown with question marks

  - by mrbamboo

  Hi, I have a header file in C++/CLR project, which contains some strings in different languages. arabic, english, german, chinese, french, japanese etc... I have a second project written in C#. Here I access the strings stored in the header file of the C++/CLR project. The encoding of the header file is Unicode - Codepage 1200 or UTF-8. the visual studio editor is able to display the strings correctly. At runtime I access these strings and assign them into a local String variable. Here I recognized that many strings are not shown correctly. Doesn't matter if I assign them or not. Accessing the original place (while debugging) shows me all the foreign strings with question marks. Especially chinese, just question marks. Example : "So?e St?ange ?ext in Ch?n?se" (This is not the best example, I know) What is the problem? I read that C# is by default UTF-16, My header file containing the strings is UTF-16 or UTF-8. I must be able to handle strings in different languages. What am I doing wrong?

  Read the article

• question about combining jquery tabs and a toggling horizontal slide panel

  - by Clay

  Hi, I'm attempting to combine a horizontally sliding panel and the ui tabs plugin. The idea is that you press a button, a panel slides open and inside is a series of tabs that expand content below. In terms of getting this to function in the most basic sense, so far so good: http://www.claylerner.com/bio_alt/ And my source looks like this: $(document).ready(function(){ $(".btn-slide").click(function(){ $("#panel").animate({width: 'toggle'}); }); }); $(function() { $("#tabs").tabs({ selected: -1 }); }); However, the problem I'm running into occurs when you have a tab exapnded and then you collapse the horizontal panel--as you can see the animation that hides the currently expanded tab looks pretty clunky. I get that this is happening because there's not a separate function hiding the expanded tab. So my question is, how can I make it so that when the button to collapse the panel (".btn-slide") is toggled it first hides any currently expanded tabs and then hides the open panel. Thanks so much!

  Read the article

• rs232 communication, general timing question

  - by Sunny Dee

  Hi, I have a piece of hardware which sends out a byte of data representing a voltage signal at a frequency of 100Hz over the serial port. I want to write a program that will read in the data so I can plot it. I know I need to open the serial port and open an inputstream. But this next part is confusing me and I'm having trouble understanding the process conceptually: I create a while loop that reads in the data from the inputstream 1 byte at a time. How do I get the while loop timing so that there is always a byte available to be read whenever it reaches the readbyte line? I'm guessing that I can't just put a sleep function inside the while loop to try and match it to the hardware sample rate. Is it just a matter of continuing reading the inputstream in the while loop, and if it's too fast then it won't do anything (since there's no new data), and if it's too slow then it will accumulate in the inputstream buffer? Like I said, i'm only trying to understand this conceptually so any guidance would be much appreciated! I'm guessing the idea is independent of which programming language I'm using, but if not, assume it is for use in Java. Thanks!

  Read the article

• Google Maps: openInfoWindowTabsHtml + GDownloadUrl (Ajax call) question

  - by Spiros

  I am facing the following problem. On an Google Map I want to add info windows with tabs, where content is loaded from an external file using the GDownloadUrl method. The code works about fine, but with two problems. a) The first time I click on a marker, nothing hapens. I need to click twice to get an info box. After that it works ok. b) When I close an info box and open it again, the tabs repeat themselves. Every time I reopen the info box, those tabs get repeated. So, if using the code below and open the info box 3 times, I get 6 tabs (Info, Photos, Info, Photos, Info, Photos). Any idea of what I am doing wrong here? I have also tried this with JQuery's $.get method, but the results are exactly the same. function createREMarker(lat,long,reID) { var reMarker = new GMarker(rePoint,iconRE); GEvent.addListener(reMarker, "click", function() { GDownloadUrl('testcontent.php?reID='+reID+'&what=info', function(data) { content1 = data; }); GDownloadUrl('testcontent.php?reID='+reID+'&what=photos', function(data) { content2 = data; }); tabs.push(new GInfoWindowTab('Info', '<div id="mapOverlayContent" style="width:375px; height:220px; overflow:auto;">'+content1+'</div>')); tabs.push(new GInfoWindowTab('Photos', '<div id="mapOverlayContent" style="width:375px; height:220px; overflow:auto;">'+content2+'</div>')); reMarker.openInfoWindowTabsHtml(tabs); }); return reMarker; };

  Read the article

• Question about WeakReferences

  - by Impz0r

  Hey there, I've got a question regarding WeakReferences. I'm right now in the process of writing a "Resource Manager" who hast to keep references to created texture objects. I have a Dictionary like: Dictionary<uint, WeakReference> Where the first is, as you allready may guessed, the Resource Id and the second param is a WeakReference to the Resource itself. Right now my Resources do have a method to free themselfes from their Owner (i.e. Resource Manager). They do so in calling a method at the Resource Manger while passing a this reference to it. The ResMgr does lookup if it is a resource he keeps bookmark of and if so, does something like this: WeakReference result; if (m_Resources.TryGetValue(ResourceId, out result)) { if (result.IsAlive) return; (result.Target as Resource).free(); // free for good m_Resources.Remove(ResourceId); } The Problem I'm having is that the part after: if (result.IsAlive) is never reached because there are still leftover references to the Resource. The thing is, I do only have one Reference of the Resource in question and it releases itself like: resource.free(); // calls internally its owner (i.e. ResMgr) resource = null; I guess the left over reference would be the "resource" variable, but I cannot set it to null, because I do have to call free first. Quite a dilema... Well what I wanted to achive with this is a Resource Manager who keeps references to its owning Resources and release them ONLY if there is no reference left to not screw up something. Any idea how I may solve this in a clean fashion? Thanks in advance! Mfg Imp

  Read the article

• JSF Managed Property question

  - by kidvid

  I have a search page that I'll called "Parent." The search page references a country lookup page that I'll call "Child." When the user selects a country on Child's page and clicks on OK, I set the country back into the parent page. I do this by calling a method on the Parent page called "UpdateCountryCodeWithLookupValue(Child child)" When the user clicks on OK on the Child page, that method gets called in the parent, wherein it'll get the selected country code out of the Child page and set it into a text entry field. My question has to do with the proper way to set up this relationship in the faces config file. The way I have it now is that the child has a managed property for the parent. I.e., in my Child page I defined a method called "SetParent(Parent parent)". Is there any drawback to doing it this way? Would it be preferable to set the managed property so that the Child page class is a property of the parent instead of vice-versa? Let's say that I could have two Parent (search) pages open at the same time, and each of these was able to open the Child page (country code lookup). What would be the ramification for that circumstance in terms of the managed property in the faces config file? Thanks, Adrian

  Read the article

• C question: error: expected ')' before '*' token

  - by lhw

  ===EDIT I apologize for not putting the pcb struct into the code snippet. There is a struct called pcb defined in above the two structs I originally posted. Namely, typedef struct{ UINT32 proc; struct pcb *link; }pcb; Hi, I asked a question regarding structs in C a few minutes ago and got an answer blazing fast. But now I'm facing another problem, namely the error in the title of this question. I'm trying to implement a simple priority queue in C using arrays of queues. However, when I try to declare a function on pcb_pQ structure, I get the above error. I have the structs clearly defined in the heard file. In the header file: typedef struct{ pcb *head; pcb *tail; SINT32 size; } pcb_Q; typedef struct pcb_pQ { pcb_Q queues[5]; SINT32 size; } pcb_pQ; Function prototype in header file: /*priority queue operations*/ VOID pcb_pq_enqueue(pcb_pQ*, pcb*); Function impelmentation in .c file: VOID pcb_pq_enqueue(pcb_pQ* pcb_pQ, pcb* pcb) { pcb_Q* pcb_Q_p; int priority; priority = pcb->proc_priority; pcb_Q_p = &pcb_pQ->queues[priority]; pcb_enqueue(pcb_Q_p, pcb); } When I try to compile the above code, I get an "error: expected ')' before '*' token". This error is pointing to the function signature in the .c file, namely VOID pcb_pq_enqueue(pcb_pQ* pcb_pQ, pcb* pcb) { But I am not sure why I am getting this error, could someone give me a hand? Thanks a lot.

  Read the article

• JQuery Post-Request question - FF doesn't get the result of the referenced php page

  - by OlliD

  Dear community, I just want to have my question posted here but just from the beginning: For a personal web project I use PHP + JQuery. Now I got stuck when I try to use the ajax posting method to send data to another php-page. I planned to have some navigational elements like next + previous on the bottom of the page by saving the user input / user given data. The code looks as follows: <div id="bottom_nav"> <div id="prev" class="flt_l"><a href="?&step=<?= $pages[$step-1] ?>">next</a></div> <div id="next" class="flt_r"><a href="?&step=<?= $pages[$step+1] ?>">previous</a></div> </div> The functionality of the page works fine. Lateron, I use the following code to sent data over via POST: $("#bottom_nav a").click( function() { alert("POST-Link: Parameter=" + $("#Parameter").val()); $.ajax( { type:"post", url:"saveParameter.php", data:"Parameter=" + $("#Parameter").val(), success: function(result) { alert(result); //$("#test").text(result); } }); }); The request itself work perfectly on IE, but on FF I'm not able to get back any result. within the PHP page, there just written: <? echo $_POST['Parameter']; ?> As IE returns the correct value, FF just provide an empty message box. I assumed that the behaviour on the -Link is different. While IE seems to handle the click event after the JS-Code execution, FF will interpret it before. My question was whether you has a solution on this regarding restructuring the code itself or using another method to reach the intened behaviour. Thanks for your assistance and recommendations, Olli

  Read the article

• C: lseek() related question.

  - by Andrei Ciobanu

  I want to write some bogus text in a file ("helloworld" text in a file called helloworld), but not starting from the beginning. I was thinking to lseek() function. If I use the following code: #include <unistd.h> #include <fcntl.h> #include <sys/stat.h> #include <sys/types.h> #include <stdlib.h> #include <stdio.h> #define fname "helloworld" #define buf_size 16 int main(){ char buffer[buf_size]; int fildes, nbytes; off_t ret; fildes = open(fname, O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR); if(fildes < 0){ printf("\nCannot create file + trunc file.\n"); } //modify offset if((ret = lseek(fildes, (off_t) 10, SEEK_END)) < (off_t) 0){ fprintf(stdout, "\nCannot modify offset.\n"); } printf("ret = %d\n", (int)ret); if(write(fildes, fname, buf_size) < 0){ fprintf(stdout, "\nWrite failed.\n"); } close(fildes); return (0); } , it compiles well and it runs without any apparent errors. Still if i : cat helloworld The output is not what I expected, but: helloworld Can Where is "Can" comming from, and where are my empty spaces ? Should i expect for "zeros" instead of spaces ? If i try to open helloworld with gedit, an error occurs, complaining that the file character encoding is unknown.

  Read the article

• Question about passing data using intents

  - by Joe K 1973

  Hi everyone, I'm trying to modify the Notepad tutorial (the Notepadv3 solution) to take in a value into the NoteEdit class, given to by the Notepadv3 class. I've successfully used .putExtra in the OnListItemClick method to place the value into the NoteEdit class, but I'm struggling to do this for the createNote method; I'm getting a force close when I try to create a new note. I bet there's a simple solution, but I'm pretty new to Java & Android and would very much appreciate your help. Here's the code in question in the Notepadv3 class: private void createNote() { Intent i = new Intent(this, NoteEdit.class); i.putExtra("key", 1); startActivityForResult(i, ACTIVITY_CREATE); } @Override protected void onListItemClick(ListView l, View v, int position, long id) { super.onListItemClick(l, v, position, id); Intent i = new Intent(this, NoteEdit.class); i.putExtra(NotesDbAdapter.KEY_ROWID, id); i.putExtra("key", 1); startActivityForResult(i, ACTIVITY_EDIT); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent intent) { super.onActivityResult(requestCode, resultCode, intent); fillData(); } And here's the receiving code in the NoteEdit class: mRowId = savedInstanceState != null ? savedInstanceState.getLong(NotesDbAdapter.KEY_ROWID) : null; if (mRowId == null) { Bundle extras = getIntent().getExtras(); mRowId = extras != null ? extras.getLong(NotesDbAdapter.KEY_ROWID) : null; value = extras.getInt("key"); } I'm fairly sure that (mRowId == null) is not true when I'm using the createNote method so therefore getExtras won't be called. One of my questions would be how can I make my NoteEdit class get this value when I use the createNote method? I'm new to this so sorry if this is a simple question for you all. Thanks, Joe

  Read the article

• Performance question: Inverting an array of pointers in-place vs array of values

  - by Anders

  The background for asking this question is that I am solving a linearized equation system (Ax=b), where A is a matrix (typically of dimension less than 100x100) and x and b are vectors. I am using a direct method, meaning that I first invert A, then find the solution by x=A^(-1)b. This step is repated in an iterative process until convergence. The way I'm doing it now, using a matrix library (MTL4): For every iteration I copy all coeffiecients of A (values) in to the matrix object, then invert. This the easiest and safest option. Using an array of pointers instead: For my particular case, the coefficients of A happen to be updated between each iteration. These coefficients are stored in different variables (some are arrays, some are not). Would there be a potential for performance gain if I set up A as an array containing pointers to these coefficient variables, then inverting A in-place? The nice thing about the last option is that once I have set up the pointers in A before the first iteration, I would not need to copy any values between successive iterations. The values which are pointed to in A would automatically be updated between iterations. So the performance question boils down to this, as I see it: - The matrix inversion process takes roughly the same amount of time, assuming de-referencing of pointers is non-expensive. - The array of pointers does not need the extra memory for matrix A containing values. - The array of pointers option does not have to copy all NxN values of A between each iteration. - The values that are pointed to the array of pointers option are generally NOT ordered in memory. Hopefully, all values lie relatively close in memory, but *A[0][1] is generally not next to *A[0][0] etc. Any comments to this? Will the last remark affect performance negatively, thus weighing up for the positive performance effects?

  Read the article

• Simple Database normalization question...

  - by user365531

  Hi all, I have a quick question regarding a database that I am designing and making sure it is normalized... I have a customer table, with a primary key of customerId. It has a StatusCode column that has a code which reflects the customers account status ie. 1 = Open, 2 = Closed, 3 = Suspended etc... Now I would like to have another field in the customer table that flags whether the account is allowed to be suspended or not... certain customers will be automatically suspended if they break there trading terms... others not... so the relevant table fields will be as so: Customers (CustomerId(PK):StatusCode:IsSuspensionAllowed) Now both fields are dependent on the primary key as you can not determine the status or whether suspensions are allowed on a particular customer unless you know the specific customer, except of course when the IsSuspensionAllowed field is set to YES, the the customer should never have a StatusCode of 3 (Suspended). It seems from the above table design it is possible for this to happen unless a check contraint is added to my table. I can't see how another table could be added to the relational design to enforce this though as it's only in the case where IsSuspensionAllowed is set to YES and StatusCode is set to 3 when the two have a dependence on each other. So after my long winded explanation my question is this: Is this a normalization problem and I'm not seeing a relational design that will enforce this... or is it actually just a business rule that should be enforced with a check contraint and the table is in fact still normalized. Cheers, Steve

  Read the article

• Algorithm Question

  - by Ravi

  Hi, I am trying to find a O (n) algorithm for this problem but unable to do so even after spending 3 - 4 hours. The brute force method times out (O (n^2)). I am confused as to how to do it ? Does the solution requires dynamic programming solution ? http://acm.timus.ru/problem.aspx?space=1&num=1794 In short the problem is this: There are some students sitting in circle and each one of them has its own choice as to when he wants to be asked a question from a teacher. The teacher will ask the questions in clockwise order only. For example: 5 3 3 1 5 5 This means that there are 5 students and : 1st student wants to go third 2nd student wants to go third 3rd student wants to go first 4th student wants to go fifth 5th student wants to go fifth. The question is as to where should teacher start asking questions so that maximum number of students will get the turn as they want. For this particular example, the answer is 5 because 3 3 1 5 5 2 3 4 5 1 You can see that by starting at fifth student as 1st, 2 students (3 and 5) are getting the choices as they wanted. For this example the answer is 12th student : 12 5 1 2 3 6 3 8 4 10 3 12 7 because 5 1 2 3 6 3 8 4 10 3 12 7 2 3 4 5 6 7 8 9 10 11 12 1 four students get their choices fulfilled. Thanks Ravi

  Read the article

• question about MySQL transaction and trigger

  - by WilliamLou

  I quickly browsed MySQL manual but didn't find the exact information about my question. Here is my question: if I have a InnoDB table A with two triggers triggered by 'AFTER INSERT ON A' and 'AFTER UPDATE ON A'. More specifically, For example: one trigger is defined as: CREATE TRIGGER test_trigger AFTER INSERT ON A FOR EACH ROW BEGIN INSERT INTO B SELECT * FROM A WHERE A.col1 = NEW.col1 END; You can ignore the query between BEGIN AND END, basically I mean this trigger will insert several rows into table B which is also a InnoDB table. Now, if I started a transaction and then insert many rows, say: 10K rows, into table A. If there is no trigger associated with table A, all these inserts are atomic, that's for sure. Now, if table A is associated with several insert/update triggers which insert/update many rows to table B and/or table C etc.. will all these inserts and/or updates are still all atomic? I think it's still atomic, but it's kind of difficult to test and I can't find any explanations in the Manual. Anyone can confirm this? Thanks a lot!

  Read the article

• c programming malloc question

  - by user535256

  Hello guys, Just got query regarding c malloc() function. I am read()ing x number of bytes from a file to get lenght of filename, like ' read(file, &namelen, sizeof(unsigned char)); ' . The variable namelen is a type unsigned char and was written into file as that type (1 byte). Now namelen has the lenght of filename ie namelen=8 if file name was 'data.txt', plus extra /0 at end, that working fine. Now I have a structure recording file info, ie filename, filelenght, content size etc. struct fileinfo { char *name; ...... other variable like size etc }; struct fileinfo *files; Question: I want to make that files.name variable the size of namelen ie 8 so I can successfully write the filename into it, like ' files[i].name = malloc(namelen) ' However, I dont want it to be malloc(sizeof(namelen)) as that would make it file.name[1] as the size of its type unsigned char. I want it to be the value thats stored inside variable &namelen ie 8 so file.name[8] so data.txt can be read() from file as 8 bytes and written straight into file.name[8? Is there a way to do this my current code is this and returns 4 not 8 files[i].name = malloc(namelen); //strlen(files[i].name) - returns 4 //perhaps something like malloc(sizeof(&namelen)) but does not work Thanks for any suggestions Have tried suggested suggestions guys, but I now get a segmentation fault error using: printf("\nsizeofnamelen=%x\n",namelen); //gives 8 for data.txt files[i].name = malloc(namelen + 1); read(file, &files[i].name, namelen); int len=strlen(files[i].name); printf("\nnamelen=%d",len); printf("\nname=%s\n",files[i].name); When I try to open() file with that files[i].name variable it wont open so the data does not appear to be getting written inside the read() &files[i].name and strlen() causes segemntation error as well as trying to print the filename

  Read the article

< Previous Page | 95 96 97 98 99 100 101 102 103 104 105 106  | Next Page >