Search Results

Search found 14169 results on 567 pages for 'parallel programming'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 201/567 | < Previous Page | 197 198 199 200 201 202 203 204 205 206 207 208  | Next Page >

  • Mapping over multiple Seq in Scala

    - by bsdfish
    Suppose I have val foo : Seq[Double] = ... val bar : Seq[Double] = ... and I wish to produce a seq where the baz(i) = foo(i) + bar(i). One way I can think of to do this is val baz : Seq[Double] = (foo.toList zip bar.toList) map ((f: Double, b : Double) => f+b) However, this feels both ugly and inefficient -- I have to convert both seqs to lists (which explodes with lazy lists), create this temporary list of tuples, only to map over it and let it be GCed. Maybe streams solve the lazy problem, but in any case, this feels like unnecessarily ugly. In lisp, the map function would map over multiple sequences. I would write (mapcar (lambda (f b) (+ f b)) foo bar) And no temporary lists would get created anywhere. Is there a map-over-multiple-lists function in Scala, or is zip combined with destructuring really the 'right' way to do this?

    Read the article

  • Better language or checking tool?

    - by rwallace
    This is primarily aimed at programmers who use unmanaged languages like C and C++ in preference to managed languages, forgoing some forms of error checking to obtain benefits like the ability to work in extremely resource constrained systems or the last increment of performance, though I would also be interested in answers from those who use managed languages. Which of the following would be of most value? A language that would optionally compile to CLR byte code or to machine code via C, and would provide things like optional array bounds checking, more support for memory management in environments where you can't use garbage collection, and faster compile times than typical C++ projects. (Think e.g. Ada or Eiffel with Python syntax.) A tool that would take existing C code and perform static analysis to look for things like potential null pointer dereferences and array overflows. (Think e.g. an open source equivalent to Coverity.) Something else I haven't thought of. Or put another way, when you're using C family languages, is the top of your wish list more expressiveness, better error checking or something else? The reason I'm asking is that I have a design and prototype parser for #1, and an outline design for #2, and I'm wondering which would be the better use of resources to work on after my current project is up and running; but I think the answers may be useful for other tools programmers also. (As usual with questions of this nature, if the answer you would give is already there, please upvote it.)

    Read the article

  • Picking the right language

    - by simion
    I am a student at University so my experience is limited, hence the question. If someone says to you, here is a task to code, what are you looking at in order to choose the language or paradigm in which you will do it in? Hope the question makes sense?

    Read the article

  • Applying a function to a custom type in F#

    - by Frederik Wordenskjold
    On my journey to learning F#, I've run into a problem I cant solve. I have defined a custom type: type BinTree = | Node of int * BinTree * BinTree | Empty I have made a function which takes a tree, traverses it, and adds the elements it visits to a list, and returns it: let rec inOrder tree = seq{ match tree with | Node (data, left, right) -> yield! inOrder left yield data; yield! inOrder right | Empty -> () } |> Seq.to_list; Now I want to create a function, similar to this, which takes a tree and a function, traverses it and applies a function to each node, then returns the tree: mapInOrder : ('a -> 'b) -> 'a BinTree -> 'b BinTree This seems easy, and it probably is! But I'm not sure how to return the tree. I've tried this: let rec mapInOrder f tree = match tree with | Node(data, left, right) -> mapInOrder f left Node(f(data), left, right) mapInOrder f right | Empty -> () but this returns a unit. I havent worked with custom types before, so I'm probably missing something there!

    Read the article

  • Exhaustive (or even just large) list of languages/stacks used for popular sites?

    - by jacko
    As a result of a conversation with a colleague today, I've been searching (unsuccessfully) for a large'ish list of what technology stacks are being used popular websites and standalone applications today. We're aware of the big ones like Facebook (php/ ), Twitter (scala/cassandra), Youtube (python/?), Digg (php/cassandra), stackoverflow (.net mvc/sqlserver), but we're looking for a more complete list. It would also be interesting to hear about any stats for desktop apps also? Can anyone help?

    Read the article

  • Is GOTO really as evil as we are led to believe?

    - by RoboShop
    I'm a young programmer, so all my working life I've been told GOTO is evil, don't use it, if you do, your first born son will die. Recently, I've realized that GOTO actually still exists in .NET and I was wondering, is GOTO really as bad as they say, or is it just because everyone says you shouldn't use it, so that's why you don't. I know GOTO can be used badly, but are there any legit situations where you may possibly use it. The only thing I can think of is maybe to use GOTO to break out of a bunch of nested loops. I reckon that might be better then having to "break" out of each of them but because GOTO is supposedly always bad, I would never use it and it would probably never pass a peer review. What are your views? Is GOTO always bad? Can it sometimes be good? Has anyone here actually been gutsy enough to use GOTO for a real life system?

    Read the article

  • How do I create Ntlm Type 1 and Type 3 messages in .Net

    - by brj011
    I need to create Type 1 message and Type 3 message for NTLM handshaking. Is there any .Net API for this? Essentially, the application is WPF based, but Socket is used in order to stream data from the server. Use of socket is a technical requirement, but the problem is when user needs to connect to the server using a proxy server. Further, if the proxy authorization is based on Ntlm, the client application needs to create Type 1 and Type 3 messages in order to handshake with the proxy server. My question is: Is there any API already available in .NET libraries that can be consumed in order to create these different types of NTLM messages? Any help or alternatives will be greatly appreciated. Thanks in advance.

    Read the article

  • What language is better suited for P2P video streaming?

    - by Roman
    I would like to write a Skype like software which allows P2P video/audio streaming. What language is better suited for that? There are several requirements: Software should be easy to install. It should be easy to program. I want to have access to video information. For example to make a face expression recognition on the fly. It should be free. I am thinking of Python and Java. Which one would be better? Or may be there is a third choice which is better? ADDED Flash is an attractive option since users can use their browser in which flash is installed by default and if not, it's easy to install flash. But I do not know if I can have access to video (if I want to do some processing). Moreover, Flash is not free.

    Read the article

  • Replace ",**" with a linebreak using RegEx (or something else)

    - by John
    I'm getting started with RegEx and I was wondering if anyone could help me craft a statement to convert coordinates as follows: 145.00694,-37.80421,9 145.00686,-37.80382,9 145.00595,-37.8035,16 145.00586,-37.80301,16 to 145.00694,-37.80421 145.00686,-37.80382 145.00595,-37.8035 145.00586,-37.80301 (Strip off the last comma and value and turn it into a line break.) I can't figure out how to use wildcards to do something like that. Any help would be greatly appreciated! Thanks.

    Read the article

  • Creating Delegates With Lambda Expressions in F#

    - by Matt H
    Why does... type IntDelegate = delegate of int -> unit type ListHelper = static member ApplyDelegate (l : int list) (d : IntDelegate) = l |> List.iter (fun x -> d.Invoke x) ListHelper.ApplyDelegate [1..10] (fun x -> printfn "%d" x) not compile, when: type IntDelegate = delegate of int -> unit type ListHelper = static member ApplyDelegate (l : int list, d : IntDelegate) = l |> List.iter (fun x -> d.Invoke x) ListHelper.ApplyDelegate ([1..10], (fun x -> printfn "%d" x)) does? The only difference that is that in the second one, ApplyDelegate takes its parameters as a tuple. Error 1 This function takes too many arguments, or is used in a context where a function is not expected

    Read the article

  • recv receiving not whole data sometime

    - by milo
    hi all, i have following issue: here is the chunk of code: void get_all_buf(int sock, std::string & inStr) { int n = 1; char c; char temp[1024*1024]; bzero(temp, sizeof(temp)); n = recv(sock, temp, sizeof(temp), 0); inStr = temp; }; but sometimes recv returning not whole data (data length always less then sizeof(temp)), only it's part. write side always sends me whole data (i got it with sniffer). what matter? thx. P.S. i know, good manner suggests me to check n (if (n < 0) perror ("error while receiving data), but it doesn't matter now - it's not reason of my problem. P.S.2 i've forgot - it's blocking socket.

    Read the article

  • Setting the rank of a user-defined verb in J

    - by Gregory Higley
    Here's a function to calculate the digital sum of a number in J: digitalSum =: +/@:("."0)@": If I use b. to query the rank of this verb, I get _ 1 _, i.e., infinite. (We can ignore the dyadic case since digitalSum is not dyadic.) I would like the monadic rank of this verb to be 0, as reported by b.. The only way I know of to do this is to use a "shim", e.g., ds =: +/@:("."0)@": digitalSum =: ds"0 This works great, but I want to know whether it's the only way to do this, or if there's something else I'm missing.

    Read the article

  • How to set buffer size in client-server app using sockets?

    - by nelly
    First of all i am new to networking so i may say dumb thing in here. Considering a client-server application using sockets(.net with c# if that matters). The client sends some data, the server process it and sends back a string. The client sends some other data, the serve process it, queries the db and sends back several hundreds of items from the database The client sends some other type of data and the server notifies some other clients . My question is how to set the buffer size correctly for reading/writing operation. Should i do something like this: byte[] buff = new byte[client.ReceiveBufferSize] ? I am thinking of something like this: Client sends data to the server(and the server will follow the same pattern) byte[] bytesToSend=new byte[2048] //2048 to be standard for any command send by the client bytes 0..1 ->command type bytes 1..2047 ->command parameters byte[] bytesToReceive=new byte[8]/byte[64]/byte[8192] //switch(command type) But..what is happening when a client is notified by the server without sending data? What is the correct way to accomplish what i am trying to do? Thanks for reading.

    Read the article

  • why copy and paste codes is dangerous

    - by Yigang Wu
    sometimes, my boss will complain us why we need so long time to implement a feature, actually, the feature has been implemented in other AP before, you just need to copy and paste codes from there. The cost should be low. It's really a hard question, because copy and paste codes is not a easy thing from my point. Do you have any good reason to explain your boss who doesn't know technology?

    Read the article

  • How much one can trust the information published in the wikipedia? [closed]

    - by AKN
    Wikipedia has answers for many question almost in all categories. Let it be Technical Sports Personalities Important events (this day, that day) Scientific terms etc... I know the source of contents are from volunteers (Please correct me if I'm wrong here). But what measures they have to ensure that contents are properly written. Even if they have admin/moderator and all that, they may not be experts in all areas. So how do they validate the appropriateness of the content?

    Read the article

  • Function templates for arbitrary STL containers containing arbitrary types.

    - by Chad Brewbaker
    I have an arbitrary STL container C, which contains elements of an arbitrary type T. I want to create an std::vector that has a copy of all the elements. What is the cleanest way to do this? template <typename C> void myfunction(C container){ /*Derive the type T of elements within the container*/ std::vector<T> mystack; /* Iterate over container and push_back() the elements into mystack*/ }

    Read the article

  • Linux - Programmatically write to a proc file

    - by Zach
    I have found several examples online where we can create a proc file, assign read and write methods that are called every time the proc file is opened for read or written to. However, I can't seem to find any documentation on how to programatically write to a proc file. Ideally, I would like to add a timestamp with other user details every time the proc file is opened for read or for write. Again, I've found where I can add the read and write functions that are triggered when the proc file is opened, but I can't find documentation on how to actually write to a proc file programatically. This would be different from a regular IO read/write, correct?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 197 198 199 200 201 202 203 204 205 206 207 208  | Next Page >