Search Results

Search found 9106 results on 365 pages for 'course'.

Page 199/365 | < Previous Page | 195 196 197 198 199 200 201 202 203 204 205 206  | Next Page >

• Is the ruby operator ||= intelligent?

  - by brad

  I have a question regarding the ||= statement in ruby and this is of particular interest to me as I'm using it to write to memcache. What I'm wondering is, does ||= check the receiver first to see if it's set before calling that setter, or is it literally an alias to x = x || y This wouldn't really matter in the case of a normal variable but using something like: CACHE[:some_key] ||= "Some String" could possibly do a memcache write which is more expensive than a simple variable set. I couldn't find anything about ||= in the ruby api oddly enough so I haven't been able to answer this myself. Of course I know that: CACHE[:some_key] = "Some String" if CACHE[:some_key].nil? would achieve this, I'm just looking for the most terse syntax.

  Read the article

• Django Inherited Field Access

  - by Rick

  As of the most current version, Django does not allow a subclass to have a variable with the same name as a variable in its superclass, if that variable is a Field instance. I need a subclass to modify this variable, which I call 'department'. Calling my classes super and sub, I need sub to modify the department variable it inherits from super. If I redeclare it, Django throws a field error. Of course, if I don't, department is not in scope for reassignment. If super has no department I get database errors. I get weird behaviour when I try rewriting init: def __init__(self): super(theSuperClass, self).__init__() TypeError: super(type, obj): obj must be an instance or subtype of type Anyone have any idea how to do this?

  Read the article

• How to stream a WAV file?

  - by jonasb

  I'm writing an app where I record audio and upload the audio file over the web. In order to speed up the upload I want to start uploading before I've finished recording. The file I'm creating is a WAV file. My plan was to use multiple data chunks. So instead of the normal encoding (RIFF, fmt , data) I’m using (RIFF, fmt , data, data, ..., data). The first issue is that the RIFF header wants the total length of the whole file, but that is of course not known when streaming the audio (I’m now using an arbitrary number). The other problem is that I'm not sure if it's valid since Audacity doesn't recognise the file, and Windows Media Player opens the file but plays only a very small part. I've been reading WAV specs but haven’t found an answer. Any suggestions?

  Read the article

• latex and listings : highlighting some parts of the code

  - by Jérôme

  I'm using Latex and the listings package to display some C++ code (with syntax highlighting) inside a document. I need to highlight some parts of the code. This specific highlight has nothing to do with syntax highlighting, it's just some parts of the code I'd like to highlight so that the reader can focus on it. I wish I could make some variable name, for instance, displaying in bold, and on a yellow background. Here is something I did with MSWord I'd like to reproduce with Latex (of course, not the red and green underlining) : . I haven't found a way to do it with the listings package. Is it possible ?

  Read the article

• Should HTTP POST be discouraged?

  - by Tomas Sedovic

  Quoting from the CouchDB documentation: It is recommended that you avoid POST when possible, because proxies and other network intermediaries will occasionally resend POST requests, which can result in duplicate document creation. To my understanding, this should not be happening on the protocol level (a confused user armed with a doubleclick is a completely different story). What is the best course of action, then? Should we really try to avoid POST requests and replace them by PUT? I don't like that as they convey a different meaning. Should we anticipate this and protect the requests by unique IDs where we want to avoid accidental duplication? I don't like that either: it complicates the code and prevents situations where multiple identical posts may be desired.

  Read the article

• C++ domain specific embedded language operators

  - by aaa

  hi. In numerical oriented languages (Matlab, Fortran) range operator and semantics is very handy when working with multidimensional data. For example: A(i:j,k,:n) // represents two-dimensional slice B(i:j,0:n) of A at index k unfortunately C++ does not have range operator (:). of course it can be emulated using range/slice functor, but semantics is less clean than Matlab. I am prototyping matrix/tensor domain language in C++ and am wondering if there any options to reproduce range operator. I still would like to rely on C++/prprocessor framework exclusively. So far I have looked through boost wave which might be an suitable option. is there any other means to introduce new operators to C++ DSL?

  Read the article

• Writing secure java code with RMI

  - by jtnire

  Hi Everyone, This may seem like a very broad question, but any help is appreciated. I have a client/server solution written in java which uses the Cajo project (which uses RMI). I just want to try and make my solution as secure as possible, given the sensitive data that will be transferred between server and client. So far, my ideas are to make all my classes "final" as well as throw a "non-serializable" exception for all my classes in the server (except for the object bound in the RMI registry, and any objects that actually do need to be transferred of course). Can anyone think of any other ideas? I know that someone could write a malicious client - this isn't hard to do as you can find out the remote object's API using reflection. However is there anything I can do to protect a malicious client access classes/objects within the server that they are not supposed to access? Many Thanks

  Read the article

• Maximum executable size on the iPhone?

  - by Sirp

  Is there a maximum size of executables or executables + shared objects on the iPhone? I've been developing an app that has been crashing on startup or early in execution with SIGSYS. Removing code from the program has helped, though structuring data so the code is simply not executed does not. This could be memory corruption, of some kind, however when I compiled with -Os rather than -O2 or -O3 the size of my executable goes down from 5.15MB to 3.60MB and the application runs perfectly. I also have a bunch of libraries I use, of course. I'm wondering, is there a limit on the size of executable code on the iPhone? Or am I just 'getting lucky' and masking memory corruption when I use -Os?

  Read the article

• Sorting by key > 10 integer sequences. with thrust

  - by smilingbuddha

  I want to perform a sort_by_key where I have a single key-sequence and multiple value sequences. One usually performs this with sort_by_key( key, key + N, make_zip_iterator( make_tuple(x1 , x2 , ...) ) ) However I want to perform a sort with 10 sequences each of length N. Thrust does not support tuples of size = 10. So is there a way around this ? Of course one can keep a separate copy of the key vector and perform sorts on bunches of 10 sequences. But I would like to do everything in a single call.

  Read the article

• How to read remote video on Amazon S3 using ffmpeg

  - by virtualize

  I need to create poster frames from videos hosted on Amazon S3 via ffmpeg. So is there a way to use the remote video file directly in ffmpeg command line like this: ffmpeg -i "http://bucket.s3.amazonaws.com/video.mp4" -ss 00:00:10 -vframes 1 -f image2 "image%03d.jpg" ffmpeg just returns: http://bucket.s3.amazonaws.com/video.mp4: I/O error occurred Usually that means that input file is truncated and/or corrupted. I also tried forcing ffmpeg to use the videos mp4 container for reading: ffmpeg -f mp4 -i "http://bucket.s3.amazonaws.com/video.mp4" ... But no luck. Wget this video from S3 and processing it locally works fine of course, as well as reading the file remotely from other 'standard' http servers. So I know that ffmpeg supports remote file reading, but why not on S3?

  Read the article

• How to retrieve an url parameter in the Zend Framework ?

  - by ismaelsow

  Hello guys ! I'am trying to retrieve an parameter passed in a url using the zend framework. But of course, it is not working ! My code looks like this : Generating the url : <?php echo $this->url(array('controller' => 'poll', 'action' => 'showresults', 'poll_id' => $poll['_id']), null, true) ?> Retrieving the "poll_id" parameter in showresultsAction() : $request = new Zend_Controller_Request_Http(); $poll_id = $request->getParam('poll_id'); The problem is that $poll_id is NULL. When I do a var_dump of $request-getParams(), it is also NULL. I have glanced trough the Zend Framework doc, but it was not very usefull. Any idea ? Thanks !

  Read the article

• Small, editable table of strings. Which Forms control do I want? (.NET)

  - by I. J. Kennedy

  I have a small array of structs, each struct has three fields, all strings. I want to display these structs in a grid, let the user edit the strings a la Excel, and then retrieve the edited strings of course. Which WinForms control is best for this? Tried a DataGridView but setting the DataSource to the array of structs doesn't seem to work. There are myriad controls with similar names but I can't figure out what does what. All the examples I've found are geared toward using a database as the data source--I just have a simple array.

  Read the article

• It's easy to set a breakpoint when debugging VBA, but how about a "startpoint" or a "skippoint"?

  - by PowerUser

  I'm debugging a subroutine in my VBA code. I want to ignore the first half and just run the second half. So, is there a way to set a 'startpoint'? Also, is there an easy way to ignore a specific line of code other than commenting? If not, I'll just continue commenting out all the code I don't want run. The problem with this, of course, is that I have to remember to uncomment the critical code before I send it on to Production.

  Read the article

• How can we block the user from unchecking a DataGridView checkbox?

  - by hawbsl

  We have a DataGridViewCheckBox column bound to a boolean property in our class. The property setter has some logic which says that under certain conditions a True flag cannot be changed, ie, it stays checked forever. This is on a per record basis. So the entire column can't be readonly, only certain rows. Pseudo code: Public Property Foo() As Boolean Get Return _Foo End Get Set(ByVal value As Boolean) If _Foo And Bar And value = False Then //do nothing, in this scenario once you're true, you stay true Else _Foo = value End If End Set End Property Databinding is handling all of this fine, except that the checkbox is visibly cleared when it's clicked. Then, of course, when the binding / setter is fired (as you move off that cell) it is restored to its checked status per the underlying logic. Ultimately it doesn't matter too much but it's a clumsy bit of UI. How can we intercept the user's click and keep it checked?

  Read the article

• SQL Compact Edition database corruption

  - by jdv

  Hi, Our product is using MS SQL Compact Edition on a Windows machine (laptop). It's basically a metadata index for files we have on the filesystem. Recently we have seen databases getting corrupted. This happens when the machine is very busy moving files around and has to do a tiny bit of database changes at the same time. I was somewhat shocked that was at all possible. It was my expectation that the database would stay coherent whatever the circumstances. Of course we are doing something wrong. Things we have checked so far are: Use of only one db connection per thread specify the maximum size when opening the database The database is accessed only by one application, a .net based windows service. Are there other gotcha's?

  Read the article

• Retrieving data from database. Retrieve only when needed or get everything?

  - by RHaguiuda

  I have a simple application to store Contacts. This application uses a simple relational database to store Contact information, like Name, Address and other data fields. While designing it, I question came to my mind: When designing programs that uses databases, should I retrieve all database records and store them in objects in my program, so I have a very fast performance or I should always gather data only when required? Of course, retrieving all data can only be done if it`s not too many, but do you use this approach when you make sure that the database will be small (< 300 records for example)? I have designed once a similar application that fetches data only when needed, but that was slow (using a Access database). Thanks for all help.

  Read the article

• GWT formating flextable & Panel create on the fly

  - by graybow

  I have a project showing comments database I put the comments in FlexTable TabelKomen and I put the text in HTML format like this: private static final int y=1; public void UpdateTabelKomen(JsArray str){ for(int i=0; i str.length(); i++){ UpdateTabelKomen(str.get(i)); } } public void UpdateTabelKomen(ImageDetailData str){ TabelKomen.setWidget(y, 0, new HTML(str.getmember + "'s comment :" + str.getkomen())); TabelKomen.getFlexCellFormatter().setWordWrap(y, 0, true); y++; } The data was shown, but my text comment is not word wraped and make my flex table wider. Of course that will ruin my web appearance. I change new HTML with new ScrolPanel(new HTML) seems not working. so How can I Format my FlexTable? is there any option beside flextable or scrollpanel?

  Read the article

• simple putStrLn in Haskell/Yampa with arrows syntax

  - by sisif

  i'm using Haskell with the Yampa FRP library which uses the arrows language extension. how can i do a simple putStrLn in a SF? mySF = proc x -> do y <- identity -< x*x putStrLn "Hello World!" ++ show y returnA -< y the arrow syntax complains about the expression not bein an arrow (of course), but even with arrows i get no output output <- identity -< putStrLn "Hello World!"

  Read the article

• Java or Python distributed compute job (on a student budget)?

  - by midget_sadhu

  I have a large dataset (c. 40G) that I want to use for some NLP (largely embarrassingly parallel) over a couple of computers in the lab, to which i do not have root access, and only 1G of user space. I experimented with hadoop, but of course this was dead in the water-- the data is stored on an external usb hard drive, and i cant load it on to the dfs because of the 1G user space cap. I have been looking into a couple of python based options (as I'd rather use NLTK instead of Java's lingpipe if I can help it), and it seems distributed compute options look like: Ipython DISCO After my hadoop experience, i am trying to make sure i try and make an informed choice -- any help on what might be more appropriate would be greatly appreciated. Amazon's EC2 etc not really an option, as i have next to no budget.

  Read the article

• Find the centroid of a polygon with weighted vertices

  - by Calle Kabo

  Hi, I know how to find the centroid (center of mass) of a regular polygon. This assumes that every part of the polygon weighs the same. But how do I calculate the centroid of a weightless polygon (made from aerogel perhaps :), where each vertex has a weight? Simplified illustration of what I mean using straight line: 5kg-----------------5kg ^center of gravity 10kg---------------5kg ^center of gravity offset du to weight of vertices Of course, I know how to calculate the center of gravity on a straight line with weighted vertices, but how do I do it on a polygon with weighted vertices? Thanks for your time!

  Read the article

• Different analyzers for each field

  - by user72185

  Hi, How can I enable different analyzers for each field in a document I'm indexing with Lucene? Example: RAMDirectory dir = new RAMDirectory(); IndexWriter iw = new IndexWriter(dir, new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_CURRENT), true, IndexWriter.MaxFieldLength.UNLIMITED); Document doc = new Document(); Field field1 = new Field("field1", someText1, Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS); Field field2 = new Field("field2", someText2, Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS); doc.Add(field1); doc.Add(field2); iw.AddDocument(doc); iw.Commit(); The analyzer is an argument to the IndexWriter, but I want to use StandardAnalyzer for field1 and SimpleAnalyzer for field2, how can I do that? The same applies when searching, of course. The correct analyzer must be applied for each field.

  Read the article

• what practical proofs are there about the Turing completeness of neural nets? what nns can execute c

  - by Albert

  I'm interested in the computational power of neural nets. It is generally accepted that recurrent neural nets are Turing complete. Now I was searching for some papers which proofs this. What I found so far: Turing computability with neural nets, Hava T. Siegelmann and Eduardo D. Sontag, 1991 I think this is only interesting from a theoretical point of view because it needs to have the neuron activity of infinite exactness (to encode the state somehow as a rational number). S. Franklin and M. Garzon, Neural computability This needs an unbounded number of neurons and also doesn't really seem to be that much practical. (Note that another question of mine tries to point out this kind of problem between such theoretical results and the practice.) I'm searching mostly for some neural net which really can execute some code which I can also simulate and test in practice. Of course, in practice, they would have some kind of limited memory. Does anyone know something like this?

  Read the article

• define method for instance of class

  - by aharon

  Let there be class Example defined as: class Example def initialize(test='hey') self.class.send(:define_method, :say_hello, lambda { test }) end end On calling Example.new; Example.new I get a warning: method redefined; discarding old say_hello. This, I conclude, must be because it defines a method in the actual class (which makes sense, from the syntax). And that, of course, would prove disastrous should there be multiple instances of Example with different values in their methods. Is there a way to create methods just for the instance of a class from inside that instance? Thanks so much.

  Read the article

• Semicolon in object variable name

  - by milkfilk

  There's a common LDAP attribute called userCertificate;binary. It actually has a semi-colon in the attribute name. In ruby, I turn an LDAP entry into a OpenStruct object called 'struct'. struct.class = OpenStruct But of course ruby thinks it's an end-of-line character. ? struct.userCertificate;binary NameError: undefined local variable or method `binary' for main:Object from (irb):52 from :0 IRB knows that the local variable is there, because it gives me struct.userCertificate;binary from the tab auto-completion. I can also see the class variable when calling struct.methods on it. struct.methods = ... "send", "methods", "userCertificate;binary=", "hash", ... It's definitely there, I can see the contents if I print the whole variable to_s(). But how can I access the local variable when it has a semicolon in it? I have workarounds for this but I thought it was an interesting problem to post.

  Read the article

• CSS cross browser compatibility on Ubuntu

  - by bhefny

  Hello, I'm currently working in web development and my default desktop is Ubuntu and I'm kind of happy with the setup and applications I got going. But I need to test web pages for cross browser compatibility while still being on Ubuntu. I have gone through hell trying to get IE7 or IE8 (with wine) to run on ubuntu and when they finally worked they were very buggy and the graphics/scrolling was insanely slow. Of course there is the option of virtual box but again, too much GBytes just to run a small application! So to all the CSS gurus out there, how can I continue with my beloved Ubuntu and still deliver a good quality (tested) page. Thank you.

  Read the article

< Previous Page | 195 196 197 198 199 200 201 202 203 204 205 206  | Next Page >