Search Results

Search found 92406 results on 3697 pages for 'code examples'.

Page 522/3697 | < Previous Page | 518 519 520 521 522 523 524 525 526 527 528 529  | Next Page >

• Is there a recommended way to communicate scientific/engineering programming to C developers?

  - by ggkmath

  Hi, I have a lot of MATLAB code that needs to get ported to C (execution speed is critical for this work) as part of a back-end process for a web application. When I attempt to outsource this code to a C developer, I assume (correct me if I'm wrong) few C developers also understand MATLAB code (things like indexing and memory management are different, etc.). I wonder if there are any C developers out there that can recommend a procedure for me to follow to best communicate what the code does? For example, should I provide the MATLAB code and explain what it's doing line by line? Or, should I just provide the math/algorithm, explain it in plain English, and let the C developer implement it with this understanding in his/her own way (e.g. can I assume the developer understands how to work with complex math (i.e. imaginary numbers), how to generate histograms, perform an FFT, etc.)? Or, is there a better method? I expect I'm not the first to need to do this, so I wonder if any C developers out there ran into this situation and can share any conventional wisdom how they'd like this task to be transferred? Thanks in advance for any comments.

  Read the article

• O(log N) == O(1) - Why not?

  - by phoku

  Whenever I consider algorithms/data structures I tend to replace the log(N) parts by constants. Oh, I know log(N) diverges - but does it matter in real world applications? log(infinity) < 100 for all practical purposes. I am really curious for real world examples where this doesn't hold. To clarify: I understand O(f(N)) I am curious about real world examples where the asymptotic behaviour matters more than the constants of the actual performance. If log(N) can be replaced by a constant it still can be replaced by a constant in O( N log N). This question is for the sake of (a) entertainment and (b) to gather arguments to use if I run (again) into a controversy about the performance of a design.

  Read the article

• Is there a programming language with be semantics close to English ?

  - by ivo s

  Most languages allow to 'tweek' to certain extend parts of the syntax (C++,C#) and/or semantics that you will be using in your code (Katahdin, lua). But I have not heard of a language that can just completely define how your code will look like. So isn't there some language which already exists that has such capabilities to override all syntax & define semantics ? Example of what I want to do is basically from the C# code below: foreach(Fruit fruit in Fruits) { if(fruit is Apple) { fruit.Price = fruit.Price/2; } } I want do be able to to write the above code in my perfect language like this: Check if any fruits are Macintosh apples and discount the price by 50%. The advantages that come to my mind looking from a coder's perspective in this "imaginary" language are: It's very clear what is going on (self descriptive) - it's plain English after all even kid would understand my program Hides all complexities which I have to write in C#. But why should I care to learn that if statements, arithmetic operators etc since there are already implemented The disadvantages that I see for a coder who will maintain this program are: Maybe you would express this program differently from me so you may not get all the information that I've expressed in my sentence Programs can be quite verbose and hard to debug but if possible to even proximate this type of syntax above maybe more people would start programming right? That would be amazing I think. I can go to work and just write an essay to draw a square on a winform like this: Create a form called MyGreetingForm. Draw a square with in the middle of MyGreetingFormwith a side of 100 points. In the middle of the square write "Hello! Click here to continue" in Arial font. In the above code the parser must basically guess that I want to use the unnamed square from the previous sentence, it'd be hard to write such a smart parser I guess, yet it's so simple what I want to do. If the user clicks on square in the middle of MyGreetingForm show MyMainForm. In the above code 'basically' the compiler must: 1)generate an event handler 2) check if there is any square in the middle of the form and if there is - 3) hide the form and show another form It looks very hard to do but it doesn't look impossible IMO to me at least approximate this (I can personally generate a parser to perform the 3 steps above np & it's basically the same that it has to do any way when you add even in c# a.MyEvent=+handler; so I don't see a problem here) so I'm thinking maybe somebody already did something like this ? Or is there some practical burden of complexity to create such a 'essay style' programming language which I can't see ? I mean what's the worse that can happen if the parser is not that good? - your program will crash so you have to re-word it:)

  Read the article

• wp7 odata v2 dataservicestate save and restore methods tombstoning example needed

  - by MIantosca

  I am looking for an example of how to use the new DataServiceState Save and Restore methods in a WP7 application in order to tombstone a datacontext - I cannot find any examples and the approach I used resulted in an exception this saves the data context correctly PhoneApplicationService.Current.State["DataContext"] = DataServiceState.Save(this.Model.Entities); this attempts to restore it after the app is re-activated var dc = (PhoneApplicationService.Current.State["DataContext"] as DataServiceState).Restore(); but throws an exception An item could not be added to the collection. When items in a DataServiceCollection are tracked by the DataServiceContext, new items cannot be added before items have been loaded into the collection. This is the same exception I get if I try to reload a datacontext that I stored "directly" (without using the DataServiceState.Save method) in the PhoneApplicationService.Current.State. I cannot find any offical documentation on the new ODATA v2 DataServiceState class or examples. thanks Michael

  Read the article

• Need Help with Page Life Cycle(I think it is screwing me up)

  - by chobo2

  Hi I have dragged a empty asp.net table onto my webform. I generate all the rows in the code behind those. Now my table gets filled up and has dropdown lists. When the user hits save I go through all the rows and update the values from the dropdownlist in the db. This works all great. However if 2 columns have each have "Present" then those 2 columns should be not be shown anymore and 2 new columns get put in its place with other dropdown lists. This all works. However you have to refresh the entire page to for the 2 columns that should go away to go away. So what I tried to do is at the end of the button click event. Clear the whole table and then regenerate it. However when I do this then my values are not saved to the database anymore for whatever reason. if (IsPostBack == false) { // check if dummy variables exist in db- If true just generate tables with values in db. If not generate them. } else { // grab the values from the database // generate tables with the values } btn click event { go through all rows in table(foreach loop) update each column in the database with cells in each row. while in foreach loop. //done } So this is how it goes and it works expect(all correct values are saved) the table is just not updated to the user. Does not work if (IsPostBack == false) { // same code as above } // if postback is true do nothing. By the time it gets to the click event it says there is zero rows in the table so nothing happens. btn click event { // same code } Fails also. if (IsPostBack == false) { // same code as above } else { // same code as above but moved into its own method. gernerateTable(); } btn click event { // update all rows // once done clear the Tables rows // call generateTable() } This last one does nothing as for some reason it does not update anything. I don't understand why. So what am I doing wrong with this life cycle something in my process is wrong. The code works just not when I want the table to be updated right away.

  Read the article

• Executing Multiple Lines in Python

  - by metashockwave

  When Python is first installed, the default setting executes users' code input line-by-line. But sometimes I need to write programs that executes multiple lines at once. Is there a setting in Python where I can change the code execution to one block at once? Thanks if (n/2) * 2 == n:; print 'Even'; else: print 'Odd' SyntaxError: invalid syntax When I tried to run the above code, I got an invalid syntax error on ELSE

  Read the article

• Most frustrating programming style you've encountered

  - by JaredPar

  When it comes to coding style I'm a pretty relaxed programmer. I'm not firmly dug into a particular coding style. I'd prefer a consistent overall style in a large code base but I'm not going to sweat every little detail of how the code is formatted. Still there are some coding styles that drive me crazy. No matter what I can't look at examples of these styles without reaching for a VIM buffer to "fix" the "problem". I can't help it. It's not even wrong, I just can't look at it for some reason. For instance the following comment style almost completely prevents me from actually being able to read the code. if (someConditional) // Comment goes here { other code } What's the most frustrating style you've encountered?

  Read the article

• How to set an alert in Selenium RC using C# in .cs file?

  - by Vijay Prasath

  Purpose: To convert the following code from Selenium IDE to RC in C#. <tr> <td>storeEval</td> <td>alert("Please Enter the Verification code");</td> <td></td> </tr> To set pause for enter Captcha value. in a loop. its working fine in IDE. Tried with the converted code it shows as the following but VS08 shows Synax error. String = selenium.GetEval("alert(\"Please Enter the Verification code\");");

  Read the article

• FRIEND_TEST in Google Test - possible circular dependency?

  - by Mihaela

  I am trying to figure out how FRIEND_TEST works in Google Tests. http://code.google.com/p/googletest/wiki/AdvancedGuide#Private_Class_Members I am looking at the following item, trying to implement it in my code: // foo.h #include "gtest/gtest_prod.h" // Defines FRIEND_TEST. class Foo { ... private: FRIEND_TEST(FooTest, BarReturnsZeroOnNull); int Bar(void* x); }; // foo_test.cc ... TEST(FooTest, BarReturnsZeroOnNull) { Foo foo; EXPECT_EQ(0, foo.Bar(NULL)); // Uses Foo's private member Bar(). } In the code above, the piece that I can't see, is that foo_test.cc must include foo.h, in order to have access to Foo and Bar(). [Perhaps it works differently for Google ? in my code, I must include it] That will result in circular dependency... Am I missing something ?

  Read the article

• Reinstantiating a GUI (JFrame) object

  - by Alex

  Hi guys, basically I want my JFrame to become a completely new JFrame object when an event is triggered. I have some code that basically calls [CODE]GUI gui = new GUI(x, y)[/CODE] the only problem I'm having is that as well as creating the new GUI object, it is not deleting the old window. Can anyone tell me how to get rid of the old window. Thanks.

  Read the article

• Setting many key/value pairs

  - by Andrew

  Hi, I'm working on a rake task which imports from a JSON feed into an ActiveRecord called Person. Person has quite a few attributes and rather than write lines of code for setting each attribute I'm trying different methods. The closest I've got is shown below. This works nicely as far as outputing to screen but when I check the values have actually been set on the ActiveRecord itself it's always nil. So it looks like I can't use .to_sym to solve my problem? Any suggestions? I should also mention that I'm just starting out with Ruby, have been doing quite a bit of Objective-c and now need to embrace the Interwebs :) http = Net::HTTP.new(url.host, url.port) http.read_timeout = 30 json = http.get(url.to_s).body parsed = JSON.parse(json) if parsed.has_key? 'code' updatePerson = Person.find_or_initialize_by_code(parsed['code']) puts updatePerson.code parsed.each do |key, value| puts "#{key} is #{value}" symkey = key.to_sym updatePerson[:symkey] = value.to_s updatePerson.save puts "#{key}....." # shows the current key puts updatePerson[:symkey] # shows the correct value puts updatePerson.first_name # a sample key, it's returning nil end

  Read the article

• IEnumerable not null but calling Count() results in Exception

  - by Draak

  I have code that's working beautifully on my development machine, but when deployed to the server is throwing null reference exception. So, I can't step through the code, but I've pinned down the culprit. But now I am puzzled. Here's the code. The question is below. Dim certs = From p In persons _ Select New Certificate( _ p.Value, _ New CertificateData.Seminar(thisEvent.Seminar.Name, _ thisEvent.StartDate.Value, _ thisEvent.EndDate.Value, _ thisEvent.Venue.City, _ thisEvent.Venue.State, _ New CertificateData.Instructor( _ staffMember.Name, _ staffMember.Titles, _ instrSignatPath))) _ With {.CertificateId = p.Key} lblMessage.Text = CStr(certs Is Nothing) lblMessage.Text = lblMessage.Text + "<br />" + CStr(certs.Count()) In the code above persons is a dictionary of custom class, and certs is of IEnumerable type. Now here's the quandary.. The first line that sets the label returns False, so certs is not null. But the second line throws an null reference exception. How is this possible?

  Read the article

• How to Transfer Large File from MS Word Add-In (VBA) to Web Server?

  - by Ian Robinson

  Overview I have a Microsoft Word Add-In, written in VBA (Visual Basic for Applications), that compresses a document and all of it's related contents (embedded media) into a zip archive. After creating the zip archive it then turns the file into a byte array and posts it to an ASMX web service. This mostly works. Issues The main issue I have is transferring large files to the web site. I can successfully upload a file that is around 40MB, but not one that is 140MB (timeout/general failure). A secondary issue is that building the byte array in the VBScript Word Add-In can fail by running out of memory on the client machine if the zip archive is too large. Potential Solutions I am considering the following options and am looking for feedback on either option or any other suggestions. Option One Opening a file stream on the client (MS Word VBA) and reading one "chunk" at a time and transmitting to ASMX web service which assembles the "chunks" into a file on the server. This has the benefit of not adding any additional dependencies or components to the application, I would only be modifying existing functionality. (Fewer dependencies is better as this solution should work in a variety of server environments and be relatively easy to set up.) Question: Are there examples of doing this or any recommended techniques (either on the client in VBA or in the web service in C#/VB.NET)? Option Two I understand WCF may provide a solution to the issue of transferring large files by "chunking" or streaming data. However, I am not very familiar with WCF, and am not sure what exactly it is capable of or if I can communicate with a WCF service from VBA. This has the downside of adding another dependency (.NET 3.0). But if using WCF is definitely a better solution I may not mind taking that dependency. Questions: Does WCF reliably support large file transfers of this nature? If so, what does this involve? Any resources or examples? Are you able to call a WCF service from VBA? Any examples?

  Read the article

• What is a practical use for a closure in JavaScript?

  - by alex

  I'm trying my hardest to wrap my head around JavaScript's closures. I get that by returning an inner function, it will have access to any variable defined in it's immediate parent. Where would this be useful to me? Perhaps I haven't quite got my head around it yet. Most of the examples I have seen online don't provide any real world code, just vague examples. Can someone show me a real world use of a closure? Is this one, for example? var warnUser = function (msg) { var calledCount = 0; return function() { calledCount++; alert(msg + '\nYou have been warned ' + calledCount + ' times.'); }; }; var warnForTamper = warnUser('You can not tamper with our HTML.'); warnForTamper(); warnForTamper(); Thanks

  Read the article

• GPL and hosted services

  - by John

  As I understand it GPL says you only have to distribute derivative code for works you distribute, i.e. if you develop internal software you can keep your code private. What happens if you develop a server application, say like Facebook or StackOverflow? The server app is not 'distributed' so what's the situation with your code in this case?

  Read the article

• No-argument method on window.external is invoked when checking with typeof

  - by janko

  Hi, I am trying to display an HTML page with embedded JavaScript code inside a System.Windows.Forms.WebBrowser control. The JavaScript code is expected to interact with the embedding environment through the window.external object. Before invoking a method on window.external, JavaScript is supposed to check for the existance of the method. If it is not there, the code should invoke a generic fallback method. // basic idea if (typeof(window.external.MyMethod) != 'undefined') { window.external.MyMethod(args); } else { window.external.Generic("MyMethod", args); } However, checking for a no-argument method with typeof seems to invoke the method already. That is, if MyMethod accepts any positive number of arguments, the code above will work perfectly; but, if MyMethod is a no-argument method, then the expression typeof(window.external.MyMethod) will not check for its type but invoke it, too. Is there any work-around to this behavior? Can I somehow escape the expression window.external.MyMethod to prevent the method call from occurring?

  Read the article

• Why There is a difference between assembly languages like Windows, Linux ?

  - by mcaaltuntas

  I am relatively new to all this low level stuff,assembly language.. and want to learn more detail. Why there is a difference between Linux, Windows Assembly languages? As I understand when I compile a C code Operating system does not really produce pure machine or assembly code, it produces OS dependent binary code.But why ? For example when I use a x86 system, CPU only understands x86 ASM am I right?.So Why we dont write pure x86 assembly code and why there are different assembly variations based on Operating system? If we would write pure ASM or OS produce pure ASM there wouldn't be binary compatilibty issues between Operating systems or Not ? I am really wondering all reasons behind them. Any detailed answer, article, book would be great. Thanks.

  Read the article

• Event Source Live streaming in Ruby on rails onError method

  - by kishorebjv

  I'm trying to implement basic rails4 code with eventsource API & Action controller live, Everything is fine but I'm not able to reach event listner . Controller code: class HomeController < ApplicationController include ActionController::Live def tester response.headers["Content-Type"] = "text/event-stream" 3.times do |n| response.stream.write "message: hellow world! \n\n" sleep 2 end end Js code: var evSource = new EventSource("/home/tester"); evSource.onopen = function (e) { console.log("OPEN state \n"+e.data); }; evSource.addEventListener('message',function(e){ console.log("EventListener .. code.."); },false); evSource.onerror = function (e) { console.log("Error State \n\n"+e.data); }; & When i reloading the page, My console output was "OPEN state" & then "Error State" as output.. event-listener code was not displaying . 1.When I'm curling the page, "message: Hellow world!" was displaying. 2.I changed in development.rb config.cache_classes = true config.eager_load = true 3. My browsers are chrome & firefox are latest versions, so no issues with them, Where I'm missing? suggestions please!

  Read the article

• Force IOException during file reading

  - by DixonD

  I have the piece of code that reads data from file. I want to force IOException in this code for testing purpose (I want to check if code throws correct custom exception in this case). Is there a some way to create a file which is protected from being read, for example? Maybe dealing with some security checks can help? Please, note that passing name to not-existent file cannot help, because FileNotFoundException has separate catch clause. Here peace of code for better undestanding of question: BufferedReader reader = null; try { reader = new BufferedReader(new FileReader(csvFile)); String rawLine; while ((rawLine = reader.readLine()) != null) { // some work is done here } } catch (FileNotFoundException e) { throw new SomeCustomException(); } catch (IOException e) { throw new SomeCustomException(); } finally { // close the input stream if (reader != null) { try { reader.close(); } catch (IOException e) { // ignore } } }

  Read the article

• Python to Java translation

  - by obelix1337

  Hello, i get quite short code of algorithm in python, but i need to translate it to Java. I didnt find any program to do that, so i will really appreciate to help translating it. I learned python a very little to know the idea how algorithm work. The biggest problem is because in python all is object and some things are made really very confuzing like sum(self.flow[(source, vertex)] for vertex, capacity in self.get_edges(source)) and "self.adj" is like hashmap with multiple values which i have no idea how to put all together. Is any better collection for this code in java? code is: [CODE] class FlowNetwork(object): def __init__(self): self.adj, self.flow, = {},{} def add_vertex(self, vertex): self.adj[vertex] = [] def get_edges(self, v): return self.adj[v] def add_edge(self, u,v,w=0): self.adj[u].append((v,w)) self.adj[v].append((u,0)) self.flow[(u,v)] = self.flow[(v,u)] = 0 def find_path(self, source, sink, path): if source == sink: return path for vertex, capacity in self.get_edges(source): residual = capacity - self.flow[(source,vertex)] edge = (source,vertex,residual) if residual > 0 and not edge in path: result = self.find_path(vertex, sink, path + [edge]) if result != None: return result def max_flow(self, source, sink): path = self.find_path(source, sink, []) while path != None: flow = min(r for u,v,r in path) for u,v,_ in path: self.flow[(u,v)] += flow self.flow[(v,u)] -= flow path = self.find_path(source, sink, []) return sum(self.flow[(source, vertex)] for vertex, capacity in self.get_edges(source)) g = FlowNetwork() map(g.add_vertex, ['s','o','p','q','r','t']) g.add_edge('s','o',3) g.add_edge('s','p',3) g.add_edge('o','p',2) g.add_edge('o','q',3) g.add_edge('p','r',2) g.add_edge('r','t',3) g.add_edge('q','r',4) g.add_edge('q','t',2) print g.max_flow('s','t') [/CODE] result of this example is "5". algorithm find max flow in graph(linked list or whatever) from source vertex "s" to destination "t". Many thanx for any idea

  Read the article

• Fibonacci Numbers in Haskell

  - by boraer

  Hi everbody I need to change my F# code to Haskell code but I am so new in Haskell and I can not this My code simply read data from keyboard if data not an integer return an error message then calculate the n fibonacci number then writes to a list after that writes the list into a txt file Here is my code open System let rec fib n = match n with |0->0 |1->1 |2->1 |n->fib(n-1)+fib(n-2);; let printFibonacci list = for i=0 to (List.length list)-1 do printf "%d " (list.Item(i));; let writeToFile list = let file = System.IO.File.Create("C:\out2.txt") let mutable s ="" let writer = new System.IO.StreamWriter(file) try for i=0 to (List.length list)-1 do s <- list.Item(i).ToString() writer.Write(s+" ") finally writer.Close() file.Dispose() printfn "Writed To File" let mutable control = true let mutable num = 0 while control do try printfn "Enter a Number:" num <- Convert.ToInt32(stdin.ReadLine()) let listFibonacci = [for i in 0 .. num-1->fib(i)] printFibonacci(listFibonacci) printfn "\n%A"(listFibonacci) writeToFile(listFibonacci) control<-false with | :? System.FormatException->printfn "Number Format Exception"; Console.ReadKey true|>ignore

  Read the article

• Javascript eval limits

  - by user117701

  Is there a limit to javascript's eval, like in lenght? I'm trying to build an app where you can store JS code in the DB, which you can later load and eval in order to execute it, but i'm reaching a limit. First of all, the code has to all be in one line. Any multiline statements are not executed. Next, i'm reaching a limit in length (i guess). If i execute the code manually, it works, but put that same code in the db, load it via ajax, and try to execute it, and it fails. Any ideas why?

  Read the article

• Illegal offset type

  - by BFTrick

  Hello, I am having trouble uploading a file through php. I check the file type at the beginning of the process and I get an error. This is the error I am getting: Warning: Illegal offset type in /balblabla/DBfunctions.inc.php on line 183 This is the printed out $_FILES var Array ( [Picture] = Array ( [name] = JPG.jpg [type] = image/jpeg [tmp_name] = /tmp/phpHlrNY8 [error] = 0 [size] = 192221 ) ) Here is the segment of code I am using that is giving me issues: function checkFile($file, $type) { if( in_array($_FILES[$file]['type'], $type) ){ // <--- LINE 183 return true; }//if return false; } // end checkFile() This is the line of code that calls the function if( checkFile( $_FILES['Picture'], array("image/jpeg") ) == true ){ //do stuff }// end if I have used this piece of code on dozens of websites on my own server so i am guessing that this is some different configuration option. How can i modify my code so that it works on this different server?

  Read the article

• regular expression: extract last 2 characters

  - by dotnet-practitioner

  what is the best way to extract last 2 characters of a string using regular expression. For example, I want to extract state code from the following "A_IL" I want to extract IL as string.. please provide me C# code on how to get it.. string fullexpression = "A_IL"; string StateCode = some regular expression code.... thanks

  Read the article

• How do C++ compilers actually pass reference parameters?

  - by T.E.D.

  This question came about as a result of some mixed-langauge programming. I had a Fortran routine I wanted to call from C++ code. Fortran passes all its parameters by reference (unless you tell it otherwise). So I thought I'd be clever (bad start right there) in my C++ code and define the Fortran routine something like this: extern "C" void FORTRAN_ROUTINE (unsigned & flag); This code worked for a while but (of course right when I needed to leave) suddenly started blowing up on a return call. Clear indication of a munged call stack. Another engineer came behind me and fixed the problem, declaring that the routine had to be deinfed in C++ as extern "C" void FORTRAN_ROUTINE (unsigned * flag); I'd accept that except for two things. One is that it seems rather counter-intuitive for the compiler to not pass reference parameters by reference, and I can find no documentation anywhere that says that. The other is that he changed a whole raft of other code in there at the same time, so it theoretically could have been another change that fixed whatever the issue was. So the question is, how does C++ actually pass reference parameters? Is it perhaps free to do copy-in, copy-out for small values or something? In other words, are reference parameters utterly useless in mixed-language programming? I'd like to know so I don't make this same code-killing mistake ever again.

  Read the article

< Previous Page | 518 519 520 521 522 523 524 525 526 527 528 529  | Next Page >