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  • Good practice of using list of function in Python

    - by riskio
    I am pretty new to python and I discovered by myself that I can create a list of function and call with a for loop. example: def a(args): print "A" def b(args): print "B" def c(args): print "C " + str(args) functions = [a,b,c] for i in functions: i(1) So, my question is: is there any good practice or elegant way to use list of functions and what is a good use of all this? (do have a particular name the "list of functions"?) thank you

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  • Reopening serial port fails if not closed properly with CloseHandle

    - by superg
    I am working with USB device on Windows that is seen as a virtual serial port. I can communicate with the device using CreateFile and ReadFile functions, but in some cases my application does not call CloseHandle (when my application in development crashes). After that all calls to CreateFile fail (ERROR_ACCESS_DENIED), and the only solution is to log in to my computer again. Is there any way to force closing the open handle (or reopening) programmatically?

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  • domain modeling naming problem

    - by cherouvim
    Hello There are some simple entities in an application (e.g containing only id and title) which rarely change and are being referenced by the more complex entities of the application. These are usually entities such as Country, City, Language etc. How are these called? I've used the following names for those in the past but I'm not sure which is the best way to call them: reference data lookup values dictionaries thanks

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  • getView() in CountDownTimer's onTick return sometimes null

    - by HexWrench
    I had recently a crash report where I could see that in the CountDownTimer's onTick method the getView() call returns null. I use the onTick method to display the remaining time in a textView. The textView is inside a Fragment. Since the CountDownTimer runs in the UI thread I have no idea why this had happened. What could be the cause for this and what is a possible workaround for this problem? Thanks!

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  • Create lags with a for-loop in R

    - by cptn
    I've got a data.frame with stock data of several companies (here it's only two). I want 10 additional columns in my stock data.frame df with lagged dates (from -5 days to +5 days) for both companies in my event data.frame. I'm using a for loop which is probably not the best solution, but it works partially. DATE <- c("01.01.2000","02.01.2000","03.01.2000","06.01.2000","07.01.2000","09.01.2000","10.01.2000","01.01.2000","02.01.2000","04.01.2000","06.01.2000","07.01.2000","09.01.2000","10.01.2000") RET <- c(-2.0,1.1,3,1.4,-0.2, 0.6, 0.1, -0.21, -1.2, 0.9, 0.3, -0.1,0.3,-0.12) COMP <- c("A","A","A","A","A","A","A","B","B","B","B","B","B","B") df <- data.frame(DATE, RET, COMP, stringsAsFactors=F) df # DATE RET COMP # 1 01.01.2000 -2.00 A # 2 02.01.2000 1.10 A # 3 03.01.2000 3.00 A # 4 06.01.2000 1.40 A # 5 07.01.2000 -0.20 A # 6 09.01.2000 0.60 A # 7 10.01.2000 0.10 A # 8 01.01.2000 -0.21 B # 9 02.01.2000 -1.20 B # 10 04.01.2000 0.90 B # 11 06.01.2000 0.30 B # 12 07.01.2000 -0.10 B # 13 09.01.2000 0.30 B # 14 10.01.2000 -0.12 B this loop works fine comp <- as.vector(unique(df$COMP)) mylist <- vector('list', length(comp)) # create lags in DATE for(i in 1:length(comp)) { print(i) comp_i <- comp[i] df_k <- df[df$COMP %in% comp_i, ] # all trading days of one firm df_k <- transform(df_k, DATEm1 = c(NA, head(DATE, -1)), DATEm2 = c(NA, NA, head(DATE, -2)), DATEm3 = c(NA, NA, NA, head(DATE, -3)), DATEm4 = c(NA, NA, NA, NA,head(DATE, -4)), DATEm5 = c(NA, NA, NA, NA, NA, head(DATE, -5)), DATEp1 = c(DATE[-1], NA)) #DATEp2 = c(DATE[-2], NA, NA), #DATEp3 = c(DATE[-3], NA, NA, NA), #DATEp4 = c(DATE[-4], NA, NA, NA, NA), #DATEp5 = c(DATE[-5], NA, NA, NA, NA, NA)) mylist[[i]] = df_k } df1 <- do.call(rbind, mylist) But if I add the lines with DATEp2, DATEp3, DATEp4, DATEp5. the code doesn't work. Can anybody tell me what I'm doing wrong here? Here the code with all the lagged dates. # create lags in DATE for(i in 1:length(comp)) { print(i) comp_i <- comp[i] df_k <- df[df$COMP %in% comp_i, ] # all trading days of one firm df_k <- transform(df_k, DATEm1 = c(NA, head(DATE, -1)), DATEm2 = c(NA, NA, head(DATE, -2)), DATEm3 = c(NA, NA, NA, head(DATE, -3)), DATEm4 = c(NA, NA, NA, NA,head(DATE, -4)), DATEm5 = c(NA, NA, NA, NA, NA, head(DATE, -5)), DATEp1 = c(DATE[-1], NA), DATEp2 = c(DATE[-2], NA, NA), DATEp3 = c(DATE[-3], NA, NA, NA), DATEp4 = c(DATE[-4], NA, NA, NA, NA), DATEp5 = c(DATE[-5], NA, NA, NA, NA, NA)) mylist[[i]] = df_k } df1 <- do.call(rbind, mylist)

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  • Asynchronous IO in Java?

    - by thr
    What options for async io (socket-based) are there in java other then java.nio? Also does java.nio use threads in the backround (as I think .NET's async-socket-library does, maybe it's been changed) or is it "true" async io using a proper select call?

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  • How do I update the system wallpaper in an Android 1.6 service after changing it with setWallpaper()

    - by Majakk
    So basically the code "almost" works - the problem is that the system does not appear to know that the system wallpaper have been changed or does not do anything about it. Starting and closing another app manually appears to enforce an update. In an event call the following is done: getApplicationContext().setWallpaper(pWallOne); Is there some way of telling the android system to update the graphics or to do some cheap trick that forces it to? Any help or tip would be very much appreciated!!

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  • WCF FaultContracts not working for Silverlight Client Proxy

    - by sarwara
    We have a Silverlight application client and a WCF Service hosted as Managed Window Service and exposing Service Contracts on BasicHttpBinding. We are sending FaultContract on the wire in case of exception is caught with the WCF Service Code. We are facing following problem as: A. If we have Synconized proxy call (in case of Window or Web Client), we are able to catch the Fault Contract. B. If we are using Silverlight Client which uses Asyncronized calls, we are unable to catch the Fault Contract. We need help on later problem (B.), Thanks in advance

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  • Calculating volume for sphere in c++

    - by Crystal
    This is probably an easy one, but is the right way to calculate volume for a sphere in c++. My getArea() seems to be right, but when I call getVolume() it doesn't output the right amount. With a sphere of radius = 1, it gives me the answer of pi, which is incorrect: double Sphere::getArea() const { return 4 * Shape::pi * pow(getZ(), 2); } double Sphere::getVolume() const { return (4 / 3) * Shape::pi * pow(getZ(), 3); }

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  • Can I make a LaTeX macro 'return' a filename?

    - by drfrogsplat
    I'm writing my thesis/dissertation and since its an on-going work I don't always have the actual images ready for the figures I put into my document, but for various reasons want to automatically have it substitute a dummy figure in place when the included graphics file doesn't exist. E.g. I can do something like \includegraphics[width=8cm]{\chapdir/figures/fluxcapacitor} (where \chapdir is a macro for my 'current' chapter directory, e.g. \def\chapdir{./ch_timetravel} and if there's no ./ch_timetravel/figures/fluxcapacitor.jpg it'll insert ./commands/dummy.jpg instead. I've structured my macros (perhaps naïvely?) so that I have a macro (\figFileOrDummy) that determines the appropriate file to include by checking if the argument provided to it exists, so that I can call \includegraphics[properties]{\figFileOrDummy{\chapdir/figures/fluxcapacitor}}. Except I'm getting various errors depending on how I try to call this, which seem to suggest that I'm approaching the problem in a fundamentally flawed way as far as 'good LaTeX programming' goes. Here's the macro to check if the file exists (and 'return' either filename or the dummy filename): \newcommand{\figFileOrDummy}[1]{% % Figure base name (no extension) to be used if the file exists \def\fodname{#1}% \def\dummyfig{commands/dummy}% % Check if output is PS (.EPS) or PDF (.JPG/.PDF/.PNG/...) figures \ifx\pdfoutput\undefined% % EPS figures only \IfFileExists{\fodname.eps}{}{\def\fodname{\dummyfig}}% \else% % Check existence of various extensions: PDF, TIF, TIFF, JPG, JPEG, PNG, MPS \def\figtest{0}% flag below compared to this value \IfFileExists{\fodname.pdf}{\def\figfilenamefound{1}}{\def\figfilenamefound{0}}% \IfFileExists{\fodname.jpg}{\def\figfilenamefound{1}}{}% \IfFileExists{\fodname.png}{\def\figfilenamefound{1}}{}% % and so on... % If no files found matching the filename (flag is 0) then use the dummy figure \ifx\figfilenamefound\figtest% \def\fodname{\dummyfig}% \fi% \fi% % 'return' the filename \fodname% }% Alternatively, here's a much simpler version which seems to have similar problems: \newcommand{\figFileOrDummy}[1]{% \def\dummyfig{commands/dummy}% \dummyfig% } The \def commands seems to be processed after the expansion of the macro they're trying to define, so it ends up being \def {commands/dummy}... (note the space after \def) and obviously complains. Also it seems to treat the literal contents of the macro as the filename for \includegraphics, rather than resolving/expanding it first, so complains that the file '\def {commands/dummy}... .png' doesn't exist.. I've tried also doing something like \edef\figfilename{\figFileOrDummy{\chapdir/figures/fluxcapacitor}} to try to force it to make \figfilename hold just the value rather than the full macro, but I get an Undefined control sequence error complaining the variables I'm trying to \def in the \figFileOrDummy macro are undefined. So my question is either How do I make this macro expand properly?; or If this is the wrong way of structuring my macros, how should I actually structure such a macro, in order to be able to insert dummy/real figures automatically?; or Is there a package that already handles this type of thing nicely that I've overlooked? I feel like I'm missing something pretty fundamental here...

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  • Can a constructor return a NULL value?

    - by Sanctus2099
    I know constructors don't "return" anything but for instance if I call CMyClass *object = new CMyClass() is there any way to make object to be NULL if the constructor fails? In my case I have some images that have to be loaded and if the file reading fails I'd like it to return null. Is there any way to do that? Thanks in advance.

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  • Does anyone know of a spell check library that underlines text?

    - by Icono123
    Does anyone know of a C# spell check library that would underline misspelled works in a windows form text box? In the past, I've used NetSpell and works great if users use the dialog box. I'm thinking I might be able to automatically call the spell check while text is being updated and underline the text. Anyone have any good ideas on what would be the best way to go about doing it?

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  • communication between remote servlets

    - by Venkatesh
    I have two web applications say App1 and App2. I want to call a servlet which is in App2 from a servlet in App1. I'm using URLConnection for this. I'm able to pass parameters to the servlet in App2 also and I'm also able to receive response from the servlet as string. But I want to send java objects from the servlet in App2 and receive them in servlet of App1. How to achieve this?

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  • Unable to read data from the transport connection: the connection was closed

    - by webdreamer
    The exception is Remoting Exception - Authentication Failure. The detailed message says "Unable to read data from the transport connection: the connection was closed." I'm having trouble with creating two simple servers that can comunicate as remote objects in C#. ServerInfo is just a class I created that holds the IP and Port and can give back the address. It works fine, as I used it before, and I've debugged it. Also the server is starting just fine, no exception is thrown, and the channel is registered without problems. I'm using Forms to do the interfaces, and call some of the methods on the server, but didn't find any problems in passing the parameters from the FormsApplication to the server when debugging. All seems fine in that chapter. public ChordServerProgram() { RemotingServices.Marshal(this, "PADIBook"); nodeInt = 0; } public void startServer() { try { serverChannel = new TcpChannel(serverInfo.Port); ChannelServices.RegisterChannel(serverChannel, true); } catch (Exception e) { Console.WriteLine(e.ToString()); } } I run two instances of this program. Then startNode is called on one of the instances of the application. The port is fine, the address generated is fine as well. As you can see, I'm using the IP for localhost, since this server is just for testing purposes. public void startNode(String portStr) { IPAddress address = IPAddress.Parse("127.0.0.1"); Int32 port = Int32.Parse(portStr); serverInfo = new ServerInfo(address, port); startServer(); //node = new ChordNode(serverInfo,this); } Then, in the other istance, through the interface again, I call another startNode method, giving it a seed server to get information from. This is where it goes wrong. When it calls the method on the seedServer proxy it just got, a RemotingException is thrown, due to an authentication failure. (The parameter I'll want to get is the node, I'm just using the int to make sure the ChordNode class has nothing to do with this error.) public void startNode(String portStr, String seedStr) { IPAddress address = IPAddress.Parse("127.0.0.1"); Int32 port = Int32.Parse(portStr); serverInfo = new ServerInfo(address, port); IPAddress addressSeed = IPAddress.Parse("127.0.0.1"); Int32 portSeed = Int32.Parse(seedStr); ServerInfo seedInfo = new ServerInfo(addressSeed, portSeed); startServer(); ChordServerProgram seedServer = (ChordServerProgram)Activator.GetObject(typeof(ChordServerProgram), seedInfo.GetFullAddress()); // node = new ChordNode(serverInfo,this); int seedNode = seedServer.nodeInt; // node.chordJoin(seedNode.self); }

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  • How to determine whether a spread-sheet cell contains a date, or a real number?

    - by Everyone
    When a cell in a spreadsheet contains a simple date (mm/dd/yyyy) the poi API flags the cell-type as 'numeric'. This is probably because spreadsheets ( IMO ) historically recognize only strings and real numbers. It is possible to hard-code the cell-index, and use it conditionally to call 'getDateCellValue'. But this feels like a hack. What other ways are there in the poi API to determine whether the content in a cell is a Date rather than a real number?

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  • Hide multiple PictureBox except clicked

    - by gadirzade
    HI Let me explain what i wont to do.I have a form and there is 10 picturebox on it.when I click one of them I wont to hide all other except clicked.It is possible that on click event of all of them hide others.but I ask for efficent way.forexample with a single function call from click event maybe

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  • Include Unit tests in the same package as the source code in Java

    - by TheDelChop
    Guys, I'm getting back into Java after a long stint in the Ruby world and I've got a question about JUnit tests and the source I'm testing. If I've got a package of graphics code for my company, lets call it com.example.graphics, should I include my tests in that package too or should they be included in a seperate package, like com.example.graphics.test? Thanks, Joe

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