Search Results

Search found 6604 results on 265 pages for 'double precision'.

Page 221/265 | < Previous Page | 217 218 219 220 221 222 223 224 225 226 227 228  | Next Page >

• Why is it a bad practice to call System.gc?

  - by zneak

  After answering to a question about how to force-free objects in Java (the guy was clearing a 1.5GB HashMap) with System.gc(), I've been told it's a bad practice to call System.gc() manually, but the comments seemed mitigated about it. So much that no one dared to upvote it, nor downvote it. I've been told there it's a bad practice, but then I've also been told garbage collector runs don't systematically stop the world anymore, and that it could also be only seen as a hint, so I'm kind of at loss. I do understand that usually the JVM knows better than you when it needs to reclaim memory. I also understand that worrying about a few kilobytes of data is silly. And I also understand that even megabytes of data isn't what it was a few years back. But still, 1.5 gigabyte? And you know there's like 1.5 GB of data hanging around in memory; it's not like it's a shot in the dark. Is System.gc() systematically bad, or is there some point at which it becomes okay? So the question is actually double: Why is it or not a bad practice to call System.gc()? Is it really a hint under certain implementations, or is it always a full collection cycle? Are there really garbage collector implementations that can do their work without stopping the world? Please shed some light over the various assertions people have made. Where's the threshold? Is it never a good idea to call System.gc(), or are there times when it's acceptable? If any, what are those times?

  Read the article

• Tailing 'Jobs' with Perl under mod_perl

  - by Matthew

  Hi everyone, I've got this project running under mod_perl shows some information on a host. On this page is a text box with a dropdown that allows users to ping/nslookup/traceroute the host. The output is shown in the text box like a tail -f. It works great under CGI. When the user requests a ping it would make an AJAX call to the server, where it essentially starts the ping with the output going to a temp file. Then subsequent ajax calls would 'tail' the file so that the output was updated until the ping finished. Once the job finished, the temp file would be removed. However, under mod_perl no matter what I do I can's stop it from creating zombie processes. I've tried everything, double forking, using IPC::Run etc. In the end, system calls are not encouraged under mod_perl. So my question is, maybe there's a better way to do this? Is there a CPAN module available for creating command line jobs and tailing output that will work under mod_perl? I'm just looking for some suggestions. I know I could probably create some sort of 'job' daemon that I signal with details and get updates from. It would run the commands and keep track of their status etc. But is there a simpler way? Thanks in advance.

  Read the article

• errors when using c++ bison ---- in the file position.hh

  - by Eric

  firstly I'm not good at English so forgive me. I compile my program with the bison generated files in visual studio and get these errors: ...\position.hh(83): error C2589: '(' : illegal token on right side of '::' ...\position.hh(83): error C2059: syntax error : '::' ...\position.hh(83): error C2589: '(' : illegal token on right side of '::' ...\position.hh(83): error C2059: syntax error : '::' and the corresponding code is: inline void columns (int count = 1) { column = std::max (1u, column + count); } I think the problem is with std::max. If I change std::max to equivalent code then there is problem anymore, but is there a better solution instead of changing the generated code? here is the *.yy file I wrote. // // bison.yy // %skeleton "lalr1.cc" %require "2.4.2" %defines %define parser_class_name "cmd_parser" %locations %debug %error-verbose %code requires { class ParserDriver; } %parse-param { ParserDriver& driver } %lex-param { ParserDriver& driver } %union { struct ast *a; double d; struct symbol *s; struct symlist *sl; int fn; } %code { #include "helper_func.h" #include "ParserDriver.h" std::string error_msg = ""; } %token <d> NUMBER %token <s> NAME %token <fn> FUNC %token EOL %token IF THEN ELSE WHILE DO LET %token SYM_TABLE_OVERFLOW %token UNKNOWN_CHARACTER %nonassoc <fn> CMP %right '=' %left '+' '-' %left '*' '/' %nonassoc '|' UMINUS %type <a> exp stmt list explist %type <sl> symlist %{ extern int yylex(yy::cmd_parser::semantic_type *yylval, yy::cmd_parser::location_type* yylloc); %} %start calclist %% ... grammar rules ...

  Read the article

• Are Large iPhone Ping Times Indicative of Application Latency?

  - by yar

  I am contemplating creating a realtime app where an iPod Touch/iPhone/iPad talks to a server-side component (which produces MIDI, and sends it onward within the host). When I ping my iPod Touch on Wifi I get huge latency (and a enormous variance, too): 64 bytes from 192.168.1.3: icmp_seq=9 ttl=64 time=38.616 ms 64 bytes from 192.168.1.3: icmp_seq=10 ttl=64 time=61.795 ms 64 bytes from 192.168.1.3: icmp_seq=11 ttl=64 time=85.162 ms 64 bytes from 192.168.1.3: icmp_seq=12 ttl=64 time=109.956 ms 64 bytes from 192.168.1.3: icmp_seq=13 ttl=64 time=31.452 ms 64 bytes from 192.168.1.3: icmp_seq=14 ttl=64 time=55.187 ms 64 bytes from 192.168.1.3: icmp_seq=15 ttl=64 time=78.531 ms 64 bytes from 192.168.1.3: icmp_seq=16 ttl=64 time=102.342 ms 64 bytes from 192.168.1.3: icmp_seq=17 ttl=64 time=25.249 ms Even if this is double what the iPhone-Host or Host-iPhone time would be, 15ms+ is too long for the app I'm considering. Is there any faster way around this (e.g., USB cable)? If not, would building the app on Android offer any other options? Traceroute reports more workable times: traceroute to 192.168.1.3 (192.168.1.3), 64 hops max, 52 byte packets 1 192.168.1.3 (192.168.1.3) 4.662 ms 3.182 ms 3.034 ms can anyone decipher this difference between ping and traceroute for me, and what they might mean for an application that needs to talk to (and from) a host?

  Read the article

• Bash and regex problem : check for tokens entered into a Coke vending machine

  - by Michael Mao

  Hi all: Here is a "challenge question" I've got from Linux system programming lecture. Any of the following strings will give you a Coke if you kick: L = { aaaa, aab, aba, baa, bb, aaaa"a", aaaa"b", aab"a", … ab"b"a, ba"b"a, ab"bbbbbb"a, ... } The letters shown in wrapped double quotes indicate coins that would have fallen through (but those strings are still part of the language in this example). Exercise (a bit hard) show this is the language of a regular expression And this is what I've got so far : #!/usr/bin/bash echo "A bottle of Coke costs you 40 cents" echo -e "Please enter tokens (a = 10 cents, b = 20 cents) in a sequence like 'abba' :\c" read tokens #if [ $tokens = aaaa ]||[ $tokens = aab ]||[ $tokens = bb ] #then # echo "Good! now a coke is yours!" #else echo "Thanks for your money, byebye!" if [[ $token =~ 'aaaa|aab|bb' ]] then echo "Good! now a coke is yours!" else echo "Thanks for your money, byebye!" fi Sadly it doesn't work... always outputs "Thanks for your money, byebye!" I believe something is wrong with syntax... We didn't provided with any good reference book and the only instruction from the professor was to consult "anything you find useful online" and "research the problem yourself" :( I know how could I do it in any programming language such as Java, but get it done with bash script + regex seems not "a bit hard" but in fact "too hard" for anyone with little knowledge on something advanced as "lookahead"(is this the terminology ?) I don't know if there is a way to express the following concept in the language of regex: Valid entry would consist of exactly one of the three components : aaaa, aab and bb, regardless of order, followed by an arbitrary sequence of a or b's So this is what is should be like : (a{4}Ua{2}bUb{2})(aUb)* where the content in first braces is order irrelevant. Thanks a lot in advance for any hints and/or tips :)

  Read the article

• C#JSON serialization

  - by Bridget the Midget

  I'm trying out the HighStock library for creating stock charts. To fill the chart with data, their example specifies this source. The first parameter is unixtime in milliseconds and the second parameter is the stock closing price. I don't know if this is valid json, but I would argue that the following would be a more appropriate way of writing json. [{"Closing":63.15000,"Date":1262559600000},{"Closing":64.75000,"Date":1262646000000}, ... I guess that I have no other option than to adapt to HighStocks syntax. I could solve this by looping and add correct syntax to a string, but that seems rudimentary. Would it be more wise to serialize C# objects to create my json, and if that's the case - how can I reach the syntax specified in the example? Lets just say this is my c# object: public class Quote { public double Date { get; set; } public decimal Closing { get; set; } } Am I making it unnecessary complex? Should I just format a json string?

  Read the article

• Types issue in F#

  - by Andry

  Hello! In my ongoing adventure deep diving into f# I am understanding a lot of this powerful language but there are things that I still do not understand so clearly. One of the most important issues I need to master is types. Well the book I am reading is very straight forward and introduces entities and main functionalities with a direct approach. The first thing I could get start with is types. It introduces the main types as list, option, tuples, and so on... It is clearly underlined that all these types are IMMUTABLE for many reasons regarding functional programming and data consistance in functional programing. Well, no problems until now... But now I am getting started with Concrete Types... Well... I have problems in managing with types like list, option, tuples, types created through new operator and concrete types created using type keyword (for abbreviations, concrete types...). So my question is: how can I efficently catalogue/distinguish all types of data in f#???? I can create a perfect separation among types in C#, VB.NET... FOr example in VB.NET there are value and reference types while in C# there are only references and also int, double are treated as objects (they are objects while in VB.NET a value type is not a object and there is a split in types for this reason). Well in F# I cannot create such differences among types in the language. Can you help me? I hope I was clear.

  Read the article

• MATLAB Easter Egg Spy vs Spy

  - by Aqui1aZ3r0

  I heard that MATLAB 2009b or earlier had a fun function. When you typed spy in the console, you would get something like this: http://t2.gstatic.com/images?q=tbn:ANd9GcSHAgKz-y1HyPHcfKvBpYmZ02PWpe3ONMDat8psEr89K0VsP_ft However, now you have an image like this:http://undocumentedmatlab.com/images/spy2.png I'd like it if I could get the code of the original spy vs spy image FYI, there's a code, but has certain errors in it: c = [';@3EA4:aei7]ced.CFHE;4\T*Y,dL0,HOQQMJLJE9PX[[Q.ZF.\JTCA1dd' '-IorRPNMPIE-Y\R8[I8]SUDW2e+' '=4BGC;7imiag2IFOQLID8''XI.]K0"PD@l32UZhP//P988_WC,U+Z^Y\<2' '&lt;82BF>?8jnjbhLJGPRMJE9/YJ/L1#QMC$;;V[iv09QE99,XD.YB,[_]=3a' '9;CG?@9kokc2MKHQSOKF:0ZL0aM2$RNG%AAW\jw9E.FEE-_G8aG.d]_W5+' '?:CDH@A:lpld3NLIRTPLG=1[M1bN3%SOH4BBX]kx:J9LLL8H9bJ/+d_dX6,' '@;DEIAB;mqmePOMJSUQMJ2\N2cO4&TPP@HCY^lyDKEMMN9+I@+S8,+deY7^' '8@EFJBC<4rnfQPNPTVRNKB3]O3dP5''UQQCIDZ_mzEPFNNOE,RA,T9/,++\8_' '9A2G3CD=544gRQPQUWUOLE4^P4"Q6(VRRIJE[n{KQKOOPK-SE.W:F/,,]Z+' ':BDH4DE>655hSRQRVXVPMF5_Q5#R>)eSSJKF\ao0L.L-WUL.VF8XCH001_[,' ';3EI<eo ?766iTSRSWYWQNG6$R6''S?*fTTlLQ]bp1M/P.XVP8[H9]DIDA=]' '?4D3=FP@877jUTSTXZXROK7%S7(TF+gUUmMR^cq:N9Q8YZQ9_IcIJEBd_^' '@5E@GQA98b3VUTUY*YSPL8&T)UI,hVhnNS_dr;PE.9Z[RCaR?+JTFC?e+' '79FA?HRB:9c4WVUVZ+ZWQM=,WG*VJ-"gi4OTes-XH+bK.#hj@PUvftDRMEF,]UH,UB.TYVWX,e\' '9;ECAKTY< ;eWYXWX\:)YSOE.YI,cL/$ikCqV1guE/PFL-^XI-YG/WZWXY1+]' ':AFDBLUZ=jgY[ZYZ-<7[XQG0[K.eN1&"$K2u:iyO9.PN9-_K8aJ9_]]82[' '?CEFDNW\?khZ[Z[==8\YRH1\M/!O2''#%m31Bw0PE/QXE8+R9bS;da^]93\' '@2FGEOX]ali[][9(ZSL2]N0"P3($&n;2Cx1QN9--L9,SA+T< +d_:4,' 'A3GHFPY^bmj\^]\]??:)[TM3^O1%Q4)%''oA:D0:0OE.8ME-TE,XB,+da;5[' '643IGQZ_cnk]_^]^@@;5\UN4_P2&R6*&(3B;E1<1PN99NL8WF.^C/,a+bY6,' '7:F3HR[dol^_^AA<6]VO5Q3''S>+'');CBF:=:QOEEOO9_G8aH6/d,cZ[Y' '8;G4IS\aep4_a-BD=7''XP6aR4(T?,(5@DCHCC;RPFLPPDH9bJ70+0d\\Z' '9BH>JT^bf45ba.CE@8(YQ7#S5)UD-)?AEDIDDD/QKMVQJ+S?cSDF,1e]a,' ':C3?K4_cg5[acbaADFA92ZR8$T6*VE.*@JFEJEEE0.NNWTK,U@+TEG0?+_bX' ';2D@L9dh6\bdcbBEGD:3[S=)U7+cK/+CKGFLIKI9/OWZUL-VA,WIHB@,`cY']; i = double(c(:)-32); j = cumsum(diff([0; i])< =0) + 1; S = sparse(i,j,1)'; spy(S)

  Read the article

• Using MinHash to find similiarities between 2 images

  - by Sung Meister

  I am using MinHash algorithm to find similar images between images. I have run across this post, How can I recognize slightly modified images? which pointed me to MinHash algorithm. Being a bit mathematically challenged, I was using a C# implementation from this blog post, Set Similarity and Min Hash. But while trying to use the implementation, I have run into 2 problems. What value should I set universe value to? When passing image byte array to HashSet, it only contains distinct byte values; thus comparing values from 1 ~ 256. What is this universe in MinHash? And what can I do to improve the C# MinHash implementation? Since HashSet<byte> contains values upto 256, similarity value always come out to 1. Here is the source that uses the C# MinHash implementation from Set Similarity and Min Hash: class Program { static void Main(string[] args) { var imageSet1 = GetImageByte(@".\Images\01.JPG"); var imageSet2 = GetImageByte(@".\Images\02.TIF"); //var app = new MinHash(256); var app = new MinHash(Math.Min(imageSet1.Count, imageSet2.Count)); double imageSimilarity = app.Similarity(imageSet1, imageSet2); Console.WriteLine("similarity = {0}", imageSimilarity); } private static HashSet<byte> GetImageByte(string imagePath) { using (var fs = new FileStream(imagePath, FileMode.Open, FileAccess.Read)) using (var br = new BinaryReader(fs)) { //List<int> bytes = br.ReadBytes((int)fs.Length).Cast<int>().ToList(); var bytes = new List<byte>(br.ReadBytes((int) fs.Length).ToArray()); return new HashSet<byte>(bytes); } } }

  Read the article

• How can I run a BitchX when I don't have ssh or shell access?

  - by Christopher

  I just installed an IRC bot, B****X (Don't ask, I don't know - the real name is not censored). I did all of the configuration and chmod'ed the pl files to 755, but running it won't work. My host does not allow SSH/Shell (which is how the documentation says to runs he script), but just going to the URL usually works because of this. However, I get a 500 (Internal Server Error) error. I have logged errors: Possible unintended interpolation of @moz in string at ./bitch.conf line 78 (#1) (W ambiguous) You said something like `@foo' in a double-quoted string but there was no array @foo in scope at the time. If you wanted a literal @foo, then write it as \@foo; otherwise find out what happened to the array you apparently lost track of. [Fri Mar 19 16:31:43 2010] bitch.pl: Possible unintended interpolation of @moz in string at ./bitch.conf line 78. Uncaught exception from user code: [Fri Mar 19 16:31:46 2010] bitch.pl: [[31mFAILED[0m] (connect error: Connection refused) at /usr/local/lib/perl5/5.8.8/CGI/Carp.pm line 354 CGI::Carp::realdie('[Fri Mar 19 16:31:46 2010] bitch.pl: [\x{1b}[31mFAILED\x{1b}[0m] (conne...') called at /usr/local/lib/perl5/5.8.8/CGI/Carp.pm line 446 CGI::Carp::die('[\x{1b}[31mFAILED\x{1b}[0m] (connect error: Connection refused)\x{a}') called at bitch.pl line 555 Thanks in advance

  Read the article

• Linux RFID reader HID Device not matching driver

  - by blietaer

  Hello, I got a RFID reader (GigaTek PCR330A-00) that is meant to be recognized under linux/windows as a (Human Interface Device) keyboard/USB. I hate to say this but it is working as a charm under Win7 but not "really" under Linux. Under Debian-like distros (x/k/Ubuntu, Debian,..), or Gentoo, or... I just can't have the device working at all: the device scan well (it has its USB 5V, so it is happy/beeping/blinking) something happened in the dmesg, but no immediate screen display of the RFID Tag code as expected (and seen under win7) Support is claiming it is ok under RHEL or SLED "enterprises" distros... and I must admit I saw it working under a RHEL4... I tried stealing the driver but did not succeed having my reader working... My question is thus double: 1./ How can I hack the kernel to add support to my device (simply register PID/VID?) ? 2./ What is different at all in a "enterprise" proprietary distro? how can I re-use it? Thank you for any hint/help. Cheers,

  Read the article

• Hi, How can I convert a dynamic web page to pdf?

  - by Jemma Diampuan

  I have a dynamic webpage that I created using html and php... I already have sample codes that can convert a static web page to pdf... But my problem is my web page is dynamic... So is there a way to convert my page to pdf? If yes, please provide some easy to understand codes... thank... Anyway, here is my code: //session variable $userID = 1; $receipt = &new Receipt(); $receipt->queryReceiptInfo($userID); $receiptID = $receipt->getReceiptID(); $receiptIssueDate = $receipt->getReceiptIssueDate(); $customer = $receipt->getCustomer(); $salesID = $receipt->getSalesID(); $salesDetail = &new SalesDetail($salesID); $salesDetails = $salesDetail->viewSalesDetail(); //session variable $businessID = 1; $business = &new Business('', $businessID); $business->queryBusinessName(); $businessName = $business->getBusinessName(); $rows = sizeof($salesDetails); $columns = sizeof($salesDetails[0]); ? Receipt No. Date Issued Business Customer Item Quantity Sub-Total "; for($j = 0; $j ".$salesDetails[$i][$j].""; } $totalPrice += (double)$salesDetails[$i][2]; echo ""; } ? Total Price

  Read the article

• Silverlight - How do I make each item in a list box be the same height?

  - by NotDan

  How can I make a silverlight listbox have all items be the same size and have them take up 100% of the listbox height. I.e. 1 item would be the height of the listbox, 2 items would each be 50% of the height of the list box, etc... Edit - Here is the code public class UniformPanel : Panel { protected override Size MeasureOverride(Size availableSize) { Size panelDesiredSize = new Size(); for (int i = 0; i < Children.Count; i++) { UIElement child = Children[i]; child.Measure(availableSize); var childDesiredSize = child.DesiredSize; panelDesiredSize.Height += childDesiredSize.Height; if (panelDesiredSize.Width < childDesiredSize.Width) { panelDesiredSize.Width = childDesiredSize.Width; } } return panelDesiredSize; } protected override Size ArrangeOverride(Size finalSize) { double height = finalSize.Height/Children.Count; for (int i = 0; i < Children.Count; i++) { UIElement child = Children[i]; Size size = new Size(finalSize.Width, height); child.Arrange(new Rect(new Point(0, i * height), size)); } return finalSize; // Returns the final Arranged size } }

  Read the article

• How do I escape ampersands in batch files?

  - by Peter Mortensen

  How do I escape ampersands in a batch file (or from the Windows command line) in order to use the start command to open web pages with ampersands in the URL? Double quotes will not work with start; this starts a new command line window instead. Update 1: Wael Dalloul's solution works. In addition, if there are URL encoded characters (e.g. space is encoded as %20) in the URL and it is in a batch file then '%' must be encoded as '%%'. This is not the case in the example. Example, from the command line (CMD.EXE): start http://www.google.com/search?client=opera&rls=en&q=escape+ampersand&sourceid=opera&ie=utf-8&oe=utf-8 will result in http://www.google.com/search?client=opera being opened in the default browser and these errors in the command line window: 'rls' is not recognized as an internal or external command, operable program or batch file. 'q' is not recognized as an internal or external command, operable program or batch file. 'sourceid' is not recognized as an internal or external command, operable program or batch file. 'ie' is not recognized as an internal or external command, operable program or batch file. 'oe' is not recognized as an internal or external command, operable program or batch file. Platform: Windows XP 64 bit SP2.

  Read the article

• unable to place breakpoints in eclipse

  - by anjanb

  I am using eclipse europa (3.5) on windows vista home premium 64-bit using JDK 1.6.0_18 (32 BIT). Normally, I am able to put breakpoints just fine; However, for a particular class which is NOT part of the project (this class is inside a .JAR file (.JAR file is part of the project) ), although I have attached a source directory to this .JAR file, I am unable to place a breakpoint in this class. If I double-click on the breakpoint pane(left border), I notice that a class breakpoint is placed. I was wondering if there was NO debug info; However, found that this particular class was compiled using ant/javac task using debug="true" and debuglevel="lines,vars,source". I even ran jad on this class to confirm that it indeed contained the debug info. So, why is eclipse preventing me from placing a breakpoint ? EDIT : Just so everyone understands the context, this is a webapp running under tomcat 6.0. I am remote debugging the application from eclipse after having started tomcat outside. The application is working just fine. I am trying to understand the behavior of the above class which I'm unable to do since eclipse is not letting me set a BP. P.S : I saw a few threads here talking about BPs not being hit but in my case, I am unable to place the BP! P.P.S : I tried JDK 1.6.0_16 before trying out 1.6.0_18. Thanks for any pointers.

  Read the article

• How to avoid loading a LINQ to SQL object twice when editting it on a website.

  - by emzero

  Hi guys I know you are all tired of this Linq-to-Sql questions, but I'm barely starting to use it (never used an ORM before) and I've already find some "ugly" things. I'm pretty used to ASP.NET Webforms old school developing, but I want to leave that behind and learn the new stuff (I've just started to read a ASP.NET MVC book and a .NET 3.5/4.0 one). So here's is one thing I didn't like and I couldn't find a good alternative to it. In most examples of editing a LINQ object I've seen the object is loaded (hitting the db) at first to fill the current values on the form page. Then, the user modify some fields and when the "Save" button is clicked, the object is loaded for second time and then updated. Here's a simplified example of ScottGu NerdDinner site. // // GET: /Dinners/Edit/5 [Authorize] public ActionResult Edit(int id) { Dinner dinner = dinnerRepository.GetDinner(id); return View(new DinnerFormViewModel(dinner)); } // // POST: /Dinners/Edit/5 [AcceptVerbs(HttpVerbs.Post), Authorize] public ActionResult Edit(int id, FormCollection collection) { Dinner dinner = dinnerRepository.GetDinner(id); UpdateModel(dinner); dinnerRepository.Save(); return RedirectToAction("Details", new { id=dinner.DinnerID }); } As you can see the dinner object is loaded two times for every modification. Unless I'm missing something about LINQ to SQL caching the last queried objects or something like that I don't like getting it twice when it should be retrieved only one time, modified and then comitted back to the database. So again, am I really missing something? Or is it really hitting the database twice (in the example above it won't harm, but there could be cases that getting an object or set of objects could be heavy stuff). If so, what alternative do you think is the best to avoid double-loading the object? Thank you so much, Greetings!

  Read the article

• Qt - no such signal error

  - by bullettime

  I'm trying to trigger a signal when a double click happens in one of the draggable widgets on the fridge magnets example. Here's the changes I made to the example source: DragLabel: class DragLabel : public QLabel { public: DragLabel(const QString &text, QWidget *parent); QString labelText() const; public slots: void testSlot(){qDebug()<<"testSlot";} //<-- implemented this slot protected: void mouseDoubleClickEvent(QMouseEvent *ev){emit testSignal();} //<-- overriden this method private: QString m_labelText; signals: void testSignal(); //<-- added this signal }; The only thing I changed in the implementation file is adding connect(this,SIGNAL(testSignal()),this,SLOT(testSlot())); to DragLabel's constructor. Trying to compile the project resulted in 'undefined reference to `DragLabel::testSignal()' and 'collect2: ld returned 1 exit status' errors. When I comment out the call to the signal, it compiles and runs, but gives off 'Object::connect: No such signal QLabel::testSignal() in draglabel.cpp' warning in the application output. Apparently testSignal() isn't being recognized as a signal. What am I missing?

  Read the article

• Binary search in a sorted (memory-mapped ?) file in Java

  - by sds

  I am struggling to port a Perl program to Java, and learning Java as I go. A central component of the original program is a Perl module that does string prefix lookups in a +500 GB sorted text file using binary search (essentially, "seek" to a byte offset in the middle of the file, backtrack to nearest newline, compare line prefix with the search string, "seek" to half/double that byte offset, repeat until found...) I have experimented with several database solutions but found that nothing beats this in sheer lookup speed with data sets of this size. Do you know of any existing Java library that implements such functionality? Failing that, could you point me to some idiomatic example code that does random access reads in text files? Alternatively, I am not familiar with the new (?) Java I/O libraries but would it be an option to memory-map the 500 GB text file (I'm on a 64-bit machine with memory to spare) and do binary search on the memory-mapped byte array? I would be very interested to hear any experiences you have to share about this and similar problems.

  Read the article

• using a JOIN in an UPDATE in SQL

  - by SDLFunTimes

  Hi, I'm having trouble formulating a legal statement to double the statuses of the suppliers (s) who have shipped (sp) more than 500 units. I've been trying: update s set s.status = s.status * 2 from s join sp on (sp.sno = s.sno) group by sno having sum(qty) > 500; however I'm getting this error from Mysql: ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'from s join sp on (sp.sno = s.sno) group by sno having sum(qty) > 500' at line 1 Does anyone have any ideas about what is wrong with this query? Here's my schema: create table s ( sno char(5) not null, sname char(20) not null, status smallint, city char(15), primary key (sno) ); create table p ( pno char(6) not null, pname char(20) not null, color char(6), weight smallint, city char(15), primary key (pno) ); create table sp ( sno char(5) not null, pno char(6) not null, qty integer not null, primary key (sno, pno) );

  Read the article

• C#: No value given for one or more required parameter with FormView

  - by Vinzcent

  Hey, I am using a FormView and when I want to update something I have edited, I always get this error: No value given for one or more required parameters. I use a SQLDataSource in combination with a FormView This is the code of my SQLDataSource <asp:SqlDataSource ID="sqldsLokaalPrinters" runat="server" ConnectionString="<%$ ConnectionStrings:connRand2 %>" DeleteCommand="DELETE FROM [tblComputers] WHERE (([tblArtveldenr] = ?) OR ([tblArtveldenr] IS NULL AND ? IS NULL))" InsertCommand="INSERT INTO [tblComputers] ([tblArtveldenr], [tblNaam], [tblCLokaal_id], [tblPositie], [tblSerienr], [tblTCPIP], [tblFabrikant], [tblModel], [tblProcessor], [tblSnelheid], [tblKleur], [tblGeheugen], [tblHarddisk], [tblZip], [tblCD], [tblDVD], [tblNetwerk], [tblFirewire], [tblAanschafdatum], [tblCLeverabcierNr], [tblScherm], [tblLaptop]) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)" ProviderName="<%$ ConnectionStrings:connRand2.ProviderName %>" SelectCommand="SELECT * FROM [tblComputers] WHERE ([tblCLokaal_id] = ?)" UpdateCommand="UPDATE [tblComputers] SET [tblNaam] = ?, [tblCLokaal_id] = ?, [tblPositie] = ?, [tblSerienr] = ?, [tblTCPIP] = ?, [tblFabrikant] = ?, [tblModel] = ?, [tblProcessor] = ?, [tblSnelheid] = ?, [tblKleur] = ?, [tblGeheugen] = ?, [tblHarddisk] = ?, [tblZip] = ?, [tblCD] = ?, [tblDVD] = ?, [tblNetwerk] = ?, [tblFirewire] = ?, [tblAanschafdatum] = ?, [tblCLeverabcierNr] = ?, [tblScherm] = ?, [tblLaptop] = ? WHERE (([tblArtveldenr] = ?) OR ([tblArtveldenr] IS NULL AND ? IS NULL))"> <SelectParameters> <asp:SessionParameter Name="tblCLokaal_id" SessionField="lokaalID" Type="Int16" /> </SelectParameters> <DeleteParameters> <asp:Parameter Name="tblArtveldenr" Type="String" /> </DeleteParameters> <UpdateParameters> <asp:Parameter Name="tblNaam" Type="String" /> <asp:Parameter Name="tblCLokaal_id" Type="Int16" /> <asp:Parameter Name="tblPositie" Type="Int32" /> <asp:Parameter Name="tblSerienr" Type="String" /> <asp:Parameter Name="tblTCPIP" Type="String" /> <asp:Parameter Name="tblFabrikant" Type="String" /> <asp:Parameter Name="tblModel" Type="String" /> <asp:Parameter Name="tblProcessor" Type="String" /> <asp:Parameter Name="tblSnelheid" Type="Int32" /> <asp:Parameter Name="tblKleur" Type="String" /> <asp:Parameter Name="tblGeheugen" Type="Int32" /> <asp:Parameter Name="tblHarddisk" Type="Double" /> <asp:Parameter Name="tblZip" Type="String" /> <asp:Parameter Name="tblCD" Type="String" /> <asp:Parameter Name="tblDVD" Type="String" /> <asp:Parameter Name="tblNetwerk" Type="String" /> <asp:Parameter Name="tblFirewire" Type="Int32" /> <asp:Parameter Name="tblAanschafdatum" Type="DateTime" /> <asp:Parameter Name="tblCLeverabcierNr" Type="Int32" /> <asp:Parameter Name="tblScherm" Type="String" /> <asp:Parameter Name="tblLaptop" Type="Boolean" /> <asp:Parameter Name="tblArtveldenr" Type="String" /> </UpdateParameters> <InsertParameters> <asp:Parameter Name="tblArtveldenr" Type="String" /> <asp:Parameter Name="tblNaam" Type="String" /> <asp:Parameter Name="tblCLokaal_id" Type="Int16" /> <asp:Parameter Name="tblPositie" Type="Int32" /> <asp:Parameter Name="tblSerienr" Type="String" /> <asp:Parameter Name="tblTCPIP" Type="String" /> <asp:Parameter Name="tblFabrikant" Type="String" /> <asp:Parameter Name="tblModel" Type="String" /> <asp:Parameter Name="tblProcessor" Type="String" /> <asp:Parameter Name="tblSnelheid" Type="Int32" /> <asp:Parameter Name="tblKleur" Type="String" /> <asp:Parameter Name="tblGeheugen" Type="Int32" /> <asp:Parameter Name="tblHarddisk" Type="Double" /> <asp:Parameter Name="tblZip" Type="String" /> <asp:Parameter Name="tblCD" Type="String" /> <asp:Parameter Name="tblDVD" Type="String" /> <asp:Parameter Name="tblNetwerk" Type="String" /> <asp:Parameter Name="tblFirewire" Type="Int32" /> <asp:Parameter Name="tblAanschafdatum" Type="DateTime" /> <asp:Parameter Name="tblCLeverabcierNr" Type="Int32" /> <asp:Parameter Name="tblScherm" Type="String" /> <asp:Parameter Name="tblLaptop" Type="Boolean" /> </InsertParameters> </asp:SqlDataSource> This is the code of my FormView <asp:FormView ID="FormView1" runat="server" AllowPaging="True" DataKeyNames="tblArtveldenr" DataSourceID="sqldsLokaalPrinters"> <EditItemTemplate> tblPositie: <asp:TextBox ID="tblPositieTextBox" runat="server" Text='<%# Bind("tblPositie") %>' /> <br /> tblSerienr: <asp:TextBox ID="tblSerienrTextBox" runat="server" Text='<%# Bind("tblSerienr") %>' /> <br /> tblFabrikant: <asp:TextBox ID="tblFabrikantTextBox" runat="server" Text='<%# Bind("tblFabrikant") %>' /> <br /> tblModel: <asp:TextBox ID="tblModelTextBox" runat="server" Text='<%# Bind("tblModel") %>' /> <br /> tblSnelheid: <asp:TextBox ID="tblSnelheidTextBox" runat="server" Text='<%# Bind("tblSnelheid") %>' /> <br /> tblHarddisk: <asp:TextBox ID="tblHarddiskTextBox" runat="server" Text='<%# Bind("tblHarddisk") %>' /> <br /> tblCD: <asp:TextBox ID="tblCDTextBox" runat="server" Text='<%# Bind("tblCD") %>' /> <br /> tblDVD: <asp:TextBox ID="tblDVDTextBox" runat="server" Text='<%# Bind("tblDVD") %>' /> <br /> tblAanschafdatum: <asp:TextBox ID="tblAanschafdatumTextBox" runat="server" Text='<%# Bind("tblAanschafdatum") %>' /> <br /> <asp:LinkButton ID="UpdateButton" runat="server" CausesValidation="True" CommandName="Update" Text="Update" /> &nbsp;<asp:LinkButton ID="UpdateCancelButton" runat="server" CausesValidation="False" CommandName="Cancel" Text="Cancel" /> </EditItemTemplate> <InsertItemTemplate> tblPositie: <asp:TextBox ID="tblPositieTextBox" runat="server" Text='<%# Bind("tblPositie") %>' /> <br /> tblSerienr: <asp:TextBox ID="tblSerienrTextBox" runat="server" Text='<%# Bind("tblSerienr") %>' /> <br /> tblFabrikant: <asp:TextBox ID="tblFabrikantTextBox" runat="server" Text='<%# Bind("tblFabrikant") %>' /> <br /> tblModel: <asp:TextBox ID="tblModelTextBox" runat="server" Text='<%# Bind("tblModel") %>' /> <br /> tblSnelheid: <asp:TextBox ID="tblSnelheidTextBox" runat="server" Text='<%# Bind("tblSnelheid") %>' /> <br /> tblHarddisk: <asp:TextBox ID="tblHarddiskTextBox" runat="server" Text='<%# Bind("tblHarddisk") %>' /> <br /> tblCD: <asp:TextBox ID="tblCDTextBox" runat="server" Text='<%# Bind("tblCD") %>' /> <br /> tblDVD: <asp:TextBox ID="tblDVDTextBox" runat="server" Text='<%# Bind("tblDVD") %>' /> <br /> tblAanschafdatum: <asp:TextBox ID="tblAanschafdatumTextBox" runat="server" Text='<%# Bind("tblAanschafdatum") %>' /> <br /> <asp:LinkButton ID="InsertButton" runat="server" CausesValidation="True" CommandName="Insert" Text="Insert" /> &nbsp;<asp:LinkButton ID="InsertCancelButton" runat="server" CausesValidation="False" CommandName="Cancel" Text="Cancel" /> </InsertItemTemplate> <ItemTemplate> tblPositie: <asp:Label ID="tblPositieLabel" runat="server" Text='<%# Bind("tblPositie") %>' /> <br /> tblSerienr: <asp:Label ID="tblSerienrLabel" runat="server" Text='<%# Bind("tblSerienr") %>' /> <br /> tblFabrikant: <asp:Label ID="tblFabrikantLabel" runat="server" Text='<%# Bind("tblFabrikant") %>' /> <br /> tblModel: <asp:Label ID="tblModelLabel" runat="server" Text='<%# Bind("tblModel") %>' /> <br /> tblSnelheid: <asp:Label ID="tblSnelheidLabel" runat="server" Text='<%# Bind("tblSnelheid") %>' /> <br /> tblHarddisk: <asp:Label ID="tblHarddiskLabel" runat="server" Text='<%# Bind("tblHarddisk") %>' /> <br /> tblCD: <asp:Label ID="tblCDLabel" runat="server" Text='<%# Bind("tblCD") %>' /> <br /> tblDVD: <asp:Label ID="tblDVDLabel" runat="server" Text='<%# Bind("tblDVD") %>' /> <br /> tblAanschafdatum: <asp:Label ID="tblAanschafdatumLabel" runat="server" Text='<%# Bind("tblAanschafdatum") %>' /> <br /> <br /> <asp:LinkButton ID="EditButton" runat="server" CausesValidation="False" CommandName="Edit" Text="Edit" /> &nbsp;<asp:LinkButton ID="DeleteButton" runat="server" CausesValidation="False" CommandName="Delete" Text="Delete" /> &nbsp;<asp:LinkButton ID="NewButton" runat="server" CausesValidation="False" CommandName="New" Text="New" /> </ItemTemplate> </asp:FormView> I have no idea how to solve this error Thanks a lot Vincent

  Read the article

• Iterator performance contract (and use on non-collections)

  - by polygenelubricants

  If all that you're doing is a simple one-pass iteration (i.e. only hasNext() and next(), no remove()), are you guaranteed linear time performance and/or amortized constant cost per operation? Is this specified in the Iterator contract anywhere? Are there data structures/Java Collection which cannot be iterated in linear time? java.util.Scanner implements Iterator<String>. A Scanner is hardly a data structure (e.g. remove() makes absolutely no sense). Is this considered a design blunder? Is something like PrimeGenerator implements Iterator<Integer> considered bad design, or is this exactly what Iterator is for? (hasNext() always returns true, next() computes the next number on demand, remove() makes no sense). Similarly, would it have made sense for java.util.Random implements Iterator<Double>? Should a type really implement Iterator if it's effectively only using one-third of its API? (i.e. no remove(), always hasNext())

  Read the article

• Overridden button control escaping content. How to stop it?

  - by RemotecUk

  Hi, I've got an ASP.Net button control that I have overridden to provide different functionality. the code looks as follows.. I'm overriding the Render method to surround the control with an <a>... /// <summary> /// Render Method /// </summary> /// <param name="writer"></param> protected override void Render(HtmlTextWriter writer) { base.CssClass = "euva-button-decorated"; writer.Write("<a class=\"euva-button\">"); base.Render(writer); writer.Write("</a>"); } When I check the generated source on the page, I find that where ASP.Net has injected its click handler it does the following... <a class="euva-button"><input type="submit" name="TestButton" value="Test Button" onclick="clickOnce(this);WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions(&quot;TestButton&quot;, &quot;&quot;, true, &quot;&quot;, &quot;&quot;, false, false))" id="TestButton" class="euva-button-decorated" /></a> ... it seems to be escaping the output for the double quotes which means that the browser cannot understand the javascript. How do I make the render method not escape the injected ASP.Net client click handler ?? Note I also have my own client click handler which is declared declaratively in the page mark-up.

  Read the article

• SharePoint 2010 / ASP.Net Integration - Looking for advice

  - by jpennal

  I have been Googling a problem that I have with trying to integrate the web application that I am working on with SharePoint 2010. The web application is a wiki style tool that allows users to log in via forms authentication or WIA against Active Directory and create content for themselves and others. What we would like to do is to allow a user have a page with the content they have created in our web application mixed in with content that they have living on the SharePoint server. For example, they may want to see a list of documents that they have on the SharePoint server mixed in with some of their content. To accomplish this, we would like to take the credentials the user has logged into our web application with (for example MYDOMAIN\jsmith) and be able to query SharePoint for the documents of that same user (MYDOMAIN\jsmith) WITHOUT the user being prompted to re-enter their credentials to access the SharePoint server (we are trying to avoid the double-hop problem) We have come up with some options for how we want to do this, but we are unsure of what the best approach is. For example, we could - Have a global user, shared by all users to get information we need from SharePoint. The downside is that we cannot filter SharePoint content to a particular user - We could store the users credentials when they log in, but that would only work for users authenticating via forms auth and would be a security issue that some users/clients would not like - Writing a SharePoint extension using WCF to allow us to access the information we need, however we'd still have the issue of figuring out how to impersonate the user we want. Neither of these options are ideal and in our investigation we came across the Claims Authentication/STS option which seems like it is trying to solve the problem we are having. So my question is, based on what I have written, is Claims/STS the best approach for us? We have not been able to find much direction on how to use this method to call into SharePoint from a Web Application and pass along the existing credentials. Does anyone have any experience with any of these issues?

  Read the article

• When *not* to use prepared statements?

  - by Ben Blank

  I'm re-engineering a PHP-driven web site which uses a minimal database. The original version used "pseudo-prepared-statements" (PHP functions which did quoting and parameter replacement) to prevent injection attacks and to separate database logic from page logic. It seemed natural to replace these ad-hoc functions with an object which uses PDO and real prepared statements, but after doing my reading on them, I'm not so sure. PDO still seems like a great idea, but one of the primary selling points of prepared statements is being able to reuse them… which I never will. Here's my setup: The statements are all trivially simple. Most are in the form SELECT foo,bar FROM baz WHERE quux = ? ORDER BY bar LIMIT 1. The most complex statement in the lot is simply three such selects joined together with UNION ALLs. Each page hit executes at most one statement and executes it only once. I'm in a hosted environment and therefore leery of slamming their servers by doing any "stress tests" personally. Given that using prepared statements will, at minimum, double the number of database round-trips I'm making, am I better off avoiding them? Can I use PDO::MYSQL_ATTR_DIRECT_QUERY to avoid the overhead of multiple database trips while retaining the benefit of parametrization and injection defense? Or do the binary calls used by the prepared statement API perform well enough compared to executing non-prepared queries that I shouldn't worry about it? EDIT: Thanks for all the good advice, folks. This is one where I wish I could mark more than one answer as "accepted" — lots of different perspectives. Ultimately, though, I have to give rick his due… without his answer I would have blissfully gone off and done the completely Wrong Thing even after following everyone's advice. :-) Emulated prepared statements it is!

  Read the article

• In asp.Net, writing code in the control tag generates compile error

  - by Nour Sabouny

  Hi this is really strange !! But look at the following asp code: <div runat="server" id="MainDiv"> <%foreach (string str in new string[]{"First#", "Second#"}) { %> <div id="<%=str.Replace("#","div") %>"> </div> <%} %> </div> now if you put this code inside any web page (and don't worry about the moral of this code, I made it just to show the idea) you'll get this error : Compiler Error Message: CS1518: Expected class, delegate, enum, interface, or struct Of course the error has nothing to do with the real problem, I searched for the code that was generated by asp.net and figured out the following : private void @__RenderMainDiv(System.Web.UI.HtmlTextWriter @__w, System.Web.UI.Control parameterContainer) { @__w.Write("\r\n "); #line 20 "blabla\blabla\Default.aspx" foreach (string str in new string[] { "First#", "Second#" }) { #line default #line hidden @__w.Write("\r\n <div id=\""); #line 22 "blabla\blabla\Default.aspx" @__w.Write(str.Replace("#", "div")); #line default #line hidden @__w.Write("\">\r\n "); } This is the code that was generated from the asp page and this is the method that is meant to render our div (MainDiv), I found out that there is a missing bracket "}" that closes the method or the (for loop). now the problem has three parts: 1- first you should have a server control (in our situation is the MainDiv) and I'm not sure if it is only the div tag. 2- HTML control inside the server control and a code inside it using the double quotation mark ( for example <div id="<%=str instead of <div id='<%=str. 3-Any keyword which has block brackets e.g.:for{},while{},using{}...etc. now removing any part, will solve the problem !!! how is this happening ?? any ideas ? BTW: please help me to make the question more obvious, because I couldn't find the best words to describe the problem.

  Read the article

< Previous Page | 217 218 219 220 221 222 223 224 225 226 227 228  | Next Page >