Search Results

Search found 9032 results on 362 pages for 'fast math'.

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 339/362 | < Previous Page | 335 336 337 338 339 340 341 342 343 344 345 346  | Next Page >

  • How to handle very frequent updates to a Lucene index

    - by fsm
    I am trying to prototype an indexing/search application which uses very volatile indexing data sources (forums, social networks etc), here are some of the performance requirements, Very fast turn-around time (by this I mean that any new data (such as a new message on a forum) should be available in the search results very soon (less than a minute)) I need to discard old documents on a fairly regular basis to ensure that the search results are not dated. Last but not least, the search application needs to be responsive. (latency on the order of 100 milliseconds, and should support at least 10 qps) All of the requirements I have currently can be met w/o using Lucene (and that would let me satisfy all 1,2 and 3), but I am anticipating other requirements in the future (like search relevance etc) which Lucene makes easier to implement. However, since Lucene is designed for use cases far more complex than the one I'm currently working on, I'm having a hard time satisfying my performance requirements. Here are some questions, a. I read that the optimize() method in the IndexWriter class is expensive, and should not be used by applications that do frequent updates, what are the alternatives? b. In order to do incremental updates, I need to keep committing new data, and also keep refreshing the index reader to make sure it has the new data available. These are going to affect 1 and 3 above. Should I try duplicate indices? What are some common approaches to solving this problem? c. I know that Lucene provides a delete method, which lets you delete all documents that match a certain query, in my case, I need to delete all documents which are older than a certain age, now one option is to add a date field to every document and use that to delete documents later. Is it possible to do range queries on document ids (I can create my own id field since I think that the one created by lucene keeps changing) to delete documents? Is it any faster than comparing dates represented as strings? I know these are very open questions, so I am not looking for a detailed answer, I will try to treat all of your answers as suggestions and use them to inform my design. Thanks! Please let me know if you need any other information.

    Read the article

  • Count seconds and minutes with MCU timer/interrupt?

    - by arynhard
    I am trying to figure out how to create a timer for my C8051F020 MCU. The following code uses the value passed to init_Timer2() with the following formula: 65535-(0.1 / (12/2000000)=48868. I set up the timer to count every time it executes and for every 10 counts, count one second. This is based on the above formula. 48868 when passed to init_Timer2 will produce a 0.1 second delay. It would take ten of them per second. However, when I test the timer it is a little fast. At ten seconds the timer reports 11 seconds, at 20 seconds the timer reports 22 seconds. I would like to get as close to a perfect second as I can. Here is my code: #include <compiler_defs.h> #include <C8051F020_defs.h> void init_Clock(void); void init_Watchdog(void); void init_Ports(void); void init_Timer2(unsigned int counts); void start_Timer2(void); void timer2_ISR(void); unsigned int timer2_Count; unsigned int seconds; unsigned int minutes; int main(void) { init_Clock(); init_Watchdog(); init_Ports(); start_Timer2(); P5 &= 0xFF; while (1); } //============================================================= //Functions //============================================================= void init_Clock(void) { OSCICN = 0x04; //2Mhz //OSCICN = 0x07; //16Mhz } void init_Watchdog(void) { //Disable watchdog timer WDTCN = 0xDE; WDTCN = 0xAD; } void init_Ports(void) { XBR0 = 0x00; XBR1 = 0x00; XBR2 = 0x40; P0 = 0x00; P0MDOUT = 0x00; P5 = 0x00; //Set P5 to 1111 P74OUT = 0x08; //Set P5 4 - 7 (LEDs) to push pull (Output) } void init_Timer2(unsigned int counts) { CKCON = 0x00; //Set all timers to system clock divided by 12 T2CON = 0x00; //Set timer 2 to timer mode RCAP2 = counts; T2 = 0xFFFF; //655535 IE |= 0x20; //Enable timer 2 T2CON |= 0x04; //Start timer 2 } void start_Timer2(void) { EA = 0; init_Timer2(48868); EA = 1; } void timer2_ISR(void) interrupt 5 { T2CON &= ~(0x80); P5 ^= 0xF0; timer2_Count++; if(timer2_Count % 10 == 0) { seconds++; } if(seconds % 60 == 0 && seconds != 0) { minutes++; } }

    Read the article

  • mysql timeout - c/C++

    - by user1262876
    Guys i'm facing a problem with this code, the problem is the timeout by timeout i mean the time it takes the program to tell me if the server is connected or not. If i use my localhost i get the answer fast, but when i connect to outside my localhost it takes 50sc - 1.5 min to response and the program frezz until it done. HOw can i fix the frezzing, or make my own timeout, like if still waiting after 50sc, tell me connection failed and stop? please use codes as help, becouse i would understand it better, thanks for any help i get PS: USING MAC #include "mysql.h" #include <stdio.h> #include <stdlib.h> // Other Linker Flags: -lmysqlclient -lm -lz // just going to input the general details and not the port numbers struct connection_details { char *server; char *user; char *password; char *database; }; MYSQL* mysql_connection_setup(struct connection_details mysql_details) { // first of all create a mysql instance and initialize the variables within MYSQL *connection = mysql_init(NULL); // connect to the database with the details attached. if (!mysql_real_connect(connection,mysql_details.server, mysql_details.user, mysql_details.password, mysql_details.database, 0, NULL, 0)) { printf("Conection error : %s\n", mysql_error(connection)); exit(1); } return connection; } MYSQL_RES* mysql_perform_query(MYSQL *connection, char *sql_query) { // send the query to the database if (mysql_query(connection, sql_query)) { printf("MySQL query error : %s\n", mysql_error(connection)); exit(1); } return mysql_use_result(connection); } int main() { MYSQL *conn; // the connection MYSQL_RES *res; // the results MYSQL_ROW row; // the results row (line by line) struct connection_details mysqlD; mysqlD.server = (char*)"Localhost"; // where the mysql database is mysqlD.user = (char*)"root"; // the root user of mysql mysqlD.password = (char*)"123456"; // the password of the root user in mysql mysqlD.database = (char*)"test"; // the databse to pick // connect to the mysql database conn = mysql_connection_setup(mysqlD); // assign the results return to the MYSQL_RES pointer res = mysql_perform_query(conn, (char*) "SELECT * FROM me"); printf("MySQL Tables in mysql database:\n"); while ((row = mysql_fetch_row(res)) !=NULL) printf("%s - %s\n", row[0], row[1], row[2]); // <-- Rows /* clean up the database result set */ mysql_free_result(res); /* clean up the database link */ mysql_close(conn); return 0; }

    Read the article

  • casting doubles to integers in order to gain speed

    - by antirez
    Hello all, in Redis (http://code.google.com/p/redis) there are scores associated to elements, in order to take this elements sorted. This scores are doubles, even if many users actually sort by integers (for instance unix times). When the database is saved we need to write this doubles ok disk. This is what is used currently: snprintf((char*)buf+1,sizeof(buf)-1,"%.17g",val); Additionally infinity and not-a-number conditions are checked in order to also represent this in the final database file. Unfortunately converting a double into the string representation is pretty slow. While we have a function in Redis that converts an integer into a string representation in a much faster way. So my idea was to check if a double could be casted into an integer without lost of data, and then using the function to turn the integer into a string if this is true. For this to provide a good speedup of course the test for integer "equivalence" must be fast. So I used a trick that is probably undefined behavior but that worked very well in practice. Something like that: double x = ... some value ... if (x == (double)((long long)x)) use_the_fast_integer_function((long long)x); else use_the_slow_snprintf(x); In my reasoning the double casting above converts the double into a long, and then back into an integer. If the range fits, and there is no decimal part, the number will survive the conversion and will be exactly the same as the initial number. As I wanted to make sure this will not break things in some system, I joined #c on freenode and I got a lot of insults ;) So I'm now trying here. Is there a standard way to do what I'm trying to do without going outside ANSI C? Otherwise, is the above code supposed to work in all the Posix systems that currently Redis targets? That is, archs where Linux / Mac OS X / *BSD / Solaris are running nowaday? What I can add in order to make the code saner is an explicit check for the range of the double before trying the cast at all. Thank you for any help.

    Read the article

  • What web platform is right for me?

    - by egervari
    I've been looking at web frameworks like Rails, Grails, etc. I'm used to doing applications in Spring Framework with Hibernate... and I want something more productive. One of the things I realized is that while some of the things in Grails is sexy, there are some serious problems with it. Grails' controllers: 1) are implemented awfully. They don't seem to be able to extend from super classes at runtime. I tried this to add base actions and helper methods, and this seems to cause grails to blow up. 2) are based on an obsolete request parameters model (rather than form backing objects, which are much nicer). 3) are hard to test. Command objects are treated totally differently... and it's actually MUCH harder to write the test than it is to write the controller code. 4) Command objects operate totally differently. They are pre-validated and bound, which causes a lot of inconsistencies than basic parameter model. 5) Command objects are not reusable, and it's a pain in the rear to reuse most of the stuff from the domain classes, like constraints and fields. This is TRIVIAL to do in basic Spring. Why the hell was it not trivial to do in Grails? 6) The scaffolding that is generated is pure crap. It doesn't generalize inserts and updates... and it actually copy/pastes a pile of code in two views: create.gsp and edit.gsp. The views themselves are gargantuan piles of doggie do-do. This is further compounded by the fact that it uses low-level parameters and not objects. Integration tests are 30x slower than a Spring integration test. It is disgusting. Some mocking tests are so hard to write and aren't guaranteed to work when it's deployed, that I think it discourages fast, tdd test cycles. Most things seem to screw up grails while it's running, like adding a taglib, or anything really. The server restart problem wasn't solved at all. I'm starting to think going with Spring/Hibernate/Java is the only way to go. While there is a pretty big cost at startup, I know it'll eventually smooth out. It sucks I can't use a language like Scala... because idiomatically, it is so incompatible with Hibernate. This app is also not a run-of-the-mill UI over a database. It's got some of that, but it's not going to be a slouch. I am deathly scared of Grails now because of how crap it is in the Controller layer. Suggestions on what I can do?

    Read the article

  • Implications of trying to double free memory space in C

    - by SidNoob
    Here' my piece of code: #include <stdio.h> #include<stdlib.h> struct student{ char *name; }; int main() { struct student s; s.name = malloc(sizeof(char *)); // I hope this is the right way... printf("Name: "); scanf("%[^\n]", s.name); printf("You Entered: \n\n"); printf("%s\n", s.name); free(s.name); // This will cause my code to break } All I know is that dynamic allocation on the 'heap' needs to be freed. My question is, when I run the program, sometimes the code runs successfully. i.e. ./struct Name: Thisis Myname You Entered: Thisis Myname I tried reading this I've concluded that I'm trying to double-free a piece of memory i.e. I'm trying to free a piece of memory that is already free? (hope I'm correct here. If Yes, what could be the Security Implications of a double-free?) While it fails sometimes as its supposed to: ./struct Name: CrazyFishMotorhead Rider You Entered: CrazyFishMotorhead Rider *** glibc detected *** ./struct: free(): invalid next size (fast): 0x08adb008 *** ======= Backtrace: ========= /lib/tls/i686/cmov/libc.so.6(+0x6b161)[0xb7612161] /lib/tls/i686/cmov/libc.so.6(+0x6c9b8)[0xb76139b8] /lib/tls/i686/cmov/libc.so.6(cfree+0x6d)[0xb7616a9d] ./struct[0x8048533] /lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe6)[0xb75bdbd6] ./struct[0x8048441] ======= Memory map: ======== 08048000-08049000 r-xp 00000000 08:01 288098 /root/struct 08049000-0804a000 r--p 00000000 08:01 288098 /root/struct 0804a000-0804b000 rw-p 00001000 08:01 288098 /root/struct 08adb000-08afc000 rw-p 00000000 00:00 0 [heap] b7400000-b7421000 rw-p 00000000 00:00 0 b7421000-b7500000 ---p 00000000 00:00 0 b7575000-b7592000 r-xp 00000000 08:01 788956 /lib/libgcc_s.so.1 b7592000-b7593000 r--p 0001c000 08:01 788956 /lib/libgcc_s.so.1 b7593000-b7594000 rw-p 0001d000 08:01 788956 /lib/libgcc_s.so.1 b75a6000-b75a7000 rw-p 00000000 00:00 0 b75a7000-b76fa000 r-xp 00000000 08:01 920678 /lib/tls/i686/cmov/libc-2.11.1.so b76fa000-b76fc000 r--p 00153000 08:01 920678 /lib/tls/i686/cmov/libc-2.11.1.so b76fc000-b76fd000 rw-p 00155000 08:01 920678 /lib/tls/i686/cmov/libc-2.11.1.so b76fd000-b7700000 rw-p 00000000 00:00 0 b7710000-b7714000 rw-p 00000000 00:00 0 b7714000-b7715000 r-xp 00000000 00:00 0 [vdso] b7715000-b7730000 r-xp 00000000 08:01 788898 /lib/ld-2.11.1.so b7730000-b7731000 r--p 0001a000 08:01 788898 /lib/ld-2.11.1.so b7731000-b7732000 rw-p 0001b000 08:01 788898 /lib/ld-2.11.1.so bffd5000-bfff6000 rw-p 00000000 00:00 0 [stack] Aborted So why is it that my code does work sometimes? i.e. the compiler is not able to detect at times that I'm trying to free an already freed memory. Has it got to do something with my stack/heap size?

    Read the article

  • File Segmentation when trying to write in a file

    - by user1286390
    I am trying in C language to use the method of bisection to find the roots of some equation, however when I try to write every step of this process in a file I get the problem "Segmentation fault". This might be an idiot fault that I did, however I have been trying to solve this for a long time. I am compiling using gcc and that is the code: #include <stdio.h> #include <stdlib.h> #include <math.h> #define R 1.0 #define h 1.0 double function(double a); void attractor(double *a1, double *a2, double *epsilon); void attractor(double *a1, double *a2, double *epsilon) { FILE* bisection; double a2_copia, a3, fa1, fa2; bisection = fopen("bisection-part1.txt", "w"); fa1 = function(*a1); fa2 = function(*a2); if(function(*a1) - function(*a2) > 0.0) *epsilon = function(*a1) - function(*a2); else *epsilon = function(*a2) - function(*a1); fprintf(bisection, "a1 a2 fa1 fa2 epsilon\n"); a2_copia = 0.0; if(function(*a1) * function(*a2) < 0.0 && *epsilon >= 0.00001) { a3 = *a2 - (*a2 - *a1); a2_copia = *a2; *a2 = a3; if(function(*a1) - function(*a2) > 0.0) *epsilon = function(*a1) - function(*a2); else *epsilon = function(*a2) - function(*a1); if(function(*a1) * function(*a2) < 0.0 && *epsilon >= 0.00001) { fprintf(bisection, "%.4f %.4f %.4f %.4f %.4f\n", *a1, *a2, function(*a1), function(*a1), *epsilon); attractor(a1, a2, epsilon); } else { *a2 = a2_copia; *a1 = a3; if(function(*a1) - function(*a2) > 0) *epsilon = function(*a1) - function(*a2); else *epsilon = function(*a2) - function(*a1); if(function(*a1) * function(*a2) < 0.0 && *epsilon >= 0.00001) { fprintf(bisection, "%.4f %.4f %.4f %.4f %.4f\n", *a1, *a2, function(*a1), function(*a1), *epsilon); attractor(a1, a2, epsilon); } } } fa1 = function(*a1); fa2 = function(*a2); if(function(*a1) - function(*a2) > 0.0) *epsilon = function(*a1) - function(*a2); else *epsilon = function(*a2) - function(*a1); fprintf(bisection, "%.4f %.4f %.4f %.4f %.4f\n", a1, a2, fa1, fa2, epsilon); } double function(double a) { double fa; fa = (a * cosh(h / (2 * a))) - R; return fa; } int main() { double a1, a2, fa1, fa2, epsilon; a1 = 0.1; a2 = 0.5; fa1 = function(a1); fa2 = function(a2); if(fa1 - fa2 > 0.0) epsilon = fa1 - fa2; else epsilon = fa2 - fa1; if(epsilon >= 0.00001) { fa1 = function(a1); fa2 = function(a2); attractor(&a1, &a2, &epsilon); fa1 = function(a1); fa2 = function(a2); if(fa1 - fa2 > 0.0) epsilon = fa1 - fa2; else epsilon = fa2 - fa1; } if(epsilon < 0.0001) printf("Vanish at %f", a2); else printf("ERROR"); return 0; } Thanks anyway and sorry if this question is not suitable.

    Read the article

  • Printing out variables in c changes values of variables

    - by George Wilson
    I have an odd problem with some c-programme here. I was getting some wrong values in a matrix I was finding the determinant of and so I started printing variables - yet found that by printing values out the actual values in the code changed. I eventually narrowed it down to one specific printf statement - highlighted in the code below. If I comment out this line then I start getting incorrect values in my determinent calculations, yet by printing it out I get the value out I expect Code below: #include <math.h> #include <stdio.h> #include <stdlib.h> #define NUMBER 15 double determinant_calculation(int size, double array[NUMBER][NUMBER]); int main() { double array[NUMBER][NUMBER], determinant_value; int size; array[0][0]=1; array[0][1]=2; array[0][2]=3; array[1][0]=4; array[1][1]=5; array[1][2]=6; array[2][0]=7; array[2][1]=8; array[2][2]=10; size=3; determinant_value=determinant_calculation(size, array); printf("\n\n\n\n\n\nDeterminant value is %lf \n\n\n\n\n\n", determinant_value); return 0; } double determinant_calculation(int size, double array[NUMBER][NUMBER]) { double determinant_matrix[NUMBER][NUMBER], determinant_value; int x, y, count=0, sign=1, i, j; /*initialises the array*/ for (i=0; i<(NUMBER); i++) { for(j=0; j<(NUMBER); j++) { determinant_matrix[i][j]=0; } } /*does the re-cursion method*/ for (count=0; count<size; count++) { x=0; y=0; for (i=0; i<size; i++) { for(j=0; j<size; j++) { if (i!=0&&j!=count) { determinant_matrix[x][y]=array[i][j]; if (y<(size-2)) { y++; } else { y=0; x++; } } } } //commenting this for loop out changes the values of the code determinent prints -7 when commented out and -3 (expected) when included! for (i=0; i<size; i++) { for(j=0; j<size; j++){ printf("%lf ", determinant_matrix[i][j]); } printf("\n"); } if(size>2) { determinant_value+=sign*(array[0][count]*determinant_calculation(size-1 ,determinant_matrix)); } else { determinant_value+=sign*(array[0][count]*determinant_matrix[0][0]); } sign=-1*sign; } return (determinant_value); } I know its not the prettiest (or best way) of doing what I'm doing with this code but it's what I've been given - so can't make huge changes. I don't suppose anyone could explain why printing out the variables can actually change the values? or how to fix it because ideally i don't want to!!

    Read the article

  • Why does the Ternary\Conditional operator seem significantly faster

    - by Jodrell
    Following on from this question, which I have partially answered. I compile this console app in x64 Release Mode, with optimizations on, and run it from the command line without a debugger attached. using System; using System.Diagnostics; class Program { static void Main() { var stopwatch = new Stopwatch(); var ternary = Looper(10, Ternary); var normal = Looper(10, Normal); if (ternary != normal) { throw new Exception(); } stopwatch.Start(); ternary = Looper(10000000, Ternary); stopWatch.Stop(); Console.WriteLine( "Ternary took {0}ms", stopwatch.ElapsedMilliseconds); stopwatch.Start(); normal = Looper(10000000, Normal); stopWatch.Stop(); Console.WriteLine( "Normal took {0}ms", stopwatch.ElapsedMilliseconds); if (ternary != normal) { throw new Exception(); } Console.ReadKey(); } static int Looper(int iterations, Func<bool, int, int> operation) { var result = 0; for (int i = 0; i < iterations; i++) { var condition = result % 11 == 4; var value = ((i * 11) / 3) % 5; result = operation(condition, value); } return result; } static int Ternary(bool condition, in value) { return value + (condition ? 2 : 1); } static int Normal(int iterations) { if (condition) { return = 2 + value; } return = 1 + value; } } I don't get any exceptions and the output to the console is somthing close to, Ternary took 107ms Normal took 230ms When I break down the CIL for the two logical functions I get this, ... Ternary ... { : ldarg.1 // push second arg : ldarg.0 // push first arg : brtrue.s T // if first arg is true jump to T : ldc.i4.1 // push int32(1) : br.s F // jump to F T: ldc.i4.2 // push int32(2) F: add // add either 1 or 2 to second arg : ret // return result } ... Normal ... { : ldarg.0 // push first arg : brfalse.s F // if first arg is false jump to F : ldc.i4.2 // push int32(2) : ldarg.1 // push second arg : add // add second arg to 2 : ret // return result F: ldc.i4.1 // push int32(1) : ldarg.1 // push second arg : add // add second arg to 1 : ret // return result } Whilst the Ternary CIL is a little shorter, it seems to me that the execution path through the CIL for either function takes 3 loads and 1 or 2 jumps and a return. Why does the Ternary function appear to be twice as fast. I underdtand that, in practice, they are both very quick and indeed, quich enough but, I would like to understand the discrepancy.

    Read the article

  • Reusing my PagedList object on WCF

    - by AlexCode
    The problem: I have a custom collection PagedList<T> that is being returned from my WCF service as PagedListOfEntitySearchResultW_SH0Zpu5 when T is EntitySearchResult object. I want to reuse this PagedList<T> type between the application and the service. My scenario: I've created a PagedList<T> type that inherits from List<T>. This type is on a separated assembly that is referenced on both application and WCF service. I'm using the /reference option on the scvutil to enable the type reusing. I also don't want any arrays returned so I also use the /collection to map to the generic List type. I'm using the following svcutil command to generate the service proxy: "C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin\NETFX 4.0 Tools\svcutil.exe" /collectionType:System.Collections.Generic.List`1 /reference:..\..\bin\Debug\App.Utilities.dll http://localhost/App.MyService/MyService.svc?wsdl /namespace:*,"App.ServiceReferences.MyService" /out:..\ServiceProxy\MyService.cs The PagedList object is something like: [CollectionDataContract] public partial class PagedList<T> : List<T> { public PagedList() { } /// <summary> /// Creates a new instance of the PagedList object and doesn't apply any pagination algorithm. /// The only calculated property is the TotalPages, everything else needed must be passed to the object. /// </summary> /// <param name="source"></param> /// <param name="pageNumber"></param> /// <param name="pageSize"></param> /// <param name="totalRecords"></param> public PagedList(IEnumerable<T> source, int pageNumber, int pageSize, int totalRecords) { if (source == null) source = new List<T>(); this.AddRange(source); PagingInfo.PageNumber = pageNumber; PageSize = pageSize; TotalRecords = totalRecords; } public PagedList(IEnumerable<T> source, PagingInfo paging) { this.AddRange(source); this._pagingInfo = paging; } [DataMember] public int TotalRecords { get; set; } [DataMember] public int PageSize { get; set; } public int TotalPages() { if (this.TotalRecords > 0 && PageSize > 0) return (int)Math.Ceiling((double)TotalRecords / (double)PageSize); else return 0; } public bool? HasPreviousPage() { return (PagingInfo.PageNumber > 1); } public bool? HasNextPage() { return (PagingInfo.PageNumber < TotalPages()); } public bool? IsFirstPage() { return PagingInfo.PageNumber == 1; } public bool? IsLastPage() { return PagingInfo.PageNumber == TotalPages(); } PagingInfo _pagingInfo = null; [DataMember] public PagingInfo PagingInfo { get { if (_pagingInfo == null) _pagingInfo = new PagingInfo(); return _pagingInfo; } set { _pagingInfo = value; } } }

    Read the article

  • Are all <canvas> tag dimensions in pixels?

    - by Simon Omega
    Are all tag dimensions in pixels? I am asking because I understood them to be. But my math is broken or I am just not grasping something here. I have been doing python mostly and just jumped back into Java Scripting. If I am just doing something stupid let me know. For a game I am writing, I wanted to have a blocky gradient. I have the following: HTML <canvas id="heir"></canvas> CSS @media screen { body { font-size: 12pt } /* Game Rendering Space */ canvas { width: 640px; height: 480px; border-style: solid; border-width: 1px; } } JavaScript (Shortened) function testDraw ( thecontext ) { var myblue = 255; thecontext.save(); // Save All Settings (Before this Function was called) for (var i = 0; i < 480; i = i + 10 ) { if (myblue.toString(16).length == 1) { thecontext.fillStyle = "#00000" + myblue.toString(16); } else { thecontext.fillStyle = "#0000" + myblue.toString(16); } thecontext.fillRect(0, i, 640, 10); myblue = myblue - 2; }; thecontext.restore(); // Restore Settings to Save Point (Removing Styles, etc...) } function main () { var targetcontext = document.getElementById(“main”).getContext("2d"); testDraw(targetcontext); } To me this should produce a series of 640w by 10h pixel bars. In Google Chrome and Fire Fox I get 15 bars. To me that means ( 480 / 15 ) is 32 pixel high bars. So I change the code to: function testDraw ( thecontext ) { var myblue = 255; thecontext.save(); // Save All Settings (Before this Function was called) for (var i = 0; i < 16; i++ ) { if (myblue.toString(16).length == 1) { thecontext.fillStyle = "#00000" + myblue.toString(16); } else { thecontext.fillStyle = "#0000" + myblue.toString(16); } thecontext.fillRect(0, (i * 10), 640, 10); myblue = myblue - 10; }; thecontext.restore(); // Restore Settings to Save Point (Removing Styles, etc...) } And get a true 32 pixel height result for comparison. Other than the fact that the first code snippet has shades of blue rendering in non-visible portions of the they are measuring 32 pixels. Now back to the Original Java Code... If I inspect the tag in Chrome it reports 640 x 480. If I inspect it in Fire Fox it reports 640 x 480. BUT! Fire Fox exports the original code to png at 300 x 150 (which is 15 rows of 10). Is it some how being resized to 640 x 480 by the CSS instead of being set to a true 640 x 480? Why, how, what? O_o I confused...

    Read the article

  • Having trouble understanding some code (Ruby on Rails)

    - by user284194
    I posted a question awhile ago asking how I could limit the rate at which a form could be submitted from a rails application. I was helped by a very patient user and their solution works great. The code was for my comments controller, and now I find myself wanting to add this functionality to another controller, my Messages controller. I immediately tried reusing the working code from the comments controller but I couldn't get it to work. Instead of asking for the working code, could someone please help me understand my working comment controller code? class CommentsController < ApplicationController #... before_filter :post_check def record_post_time cookies[:last_post_at] = Time.now.to_i end def last_post_time Time.at((cookies[:last_post_at].to_i rescue 0)) end MIN_POST_TIME = 2.minutes def post_check return true if (Time.now - last_post_time) > MIN_POST_TIME flash[:warning] = "You are trying to reply too fast." @message = Message.find(params[:message_id]) redirect_to(@message) return false end #... def create @message = Message.find(params[:message_id]) @comment = @message.comments.build(params[:comment]) if @comment.save record_post_time flash[:notice] = "Replied to \"#{@message.title}\"" redirect_to(@message) else render :action => "new" end end def update @message = Message.find(params[:message_id]) @comment = Comment.find(params[:id]) if @comment.update_attributes(params[:comment]) record_post_time redirect_to post_comment_url(@message, @comment) else render :action => "edit" end end #... end My Messages controller is pretty much a standard rails generated controller with a few before filters and associated private methods for DRYing up the code and a redirect for non existent pages. I'll explain how much of the code I understand. When a comment is created, a cookie is created with a last_post_time value. If they try to post another comment, the cookie is checked if the last one was made in the last two minutes. If it was a flash warning is displayed and no comment is recorded. What I don't really understand is how the post_check method works and how I can adapt it for my simpler posts controller. I thought I could reuse all the code in the message controller with the exception of the line: @message = Message.find(params[:message_id]) # (don't need the redirect code) in the post_check method. But it trips up on the "record_post_time" in the create action/method. I really want to understand this. Can someone explain why this doesn't work? I greatly appreciate you reading my lengthy question.

    Read the article

  • Java curious Loop Performance

    - by user1680583
    I have a big problem while evaluate my java code. To simplify the problem I wrote the following code which produce the same curious behavior. Important is the method run() and given double value rate. For my runtime test (in the main method) I set the rate to 0.5 one times and 1.0 the other time. With the value 1.0 the if-statement will be executed in each loop iteration and with the value 0.5 the if-statement will be executed half as much. For this reason I expected longer runtime by the first case but opposite is true. Can anybody explain me this phenomenon?? The result of main: Test mit rate = 0.5 Length: 50000000, IF executions: 25000856 Execution time was 4329 ms. Length: 50000000, IF executions: 24999141 Execution time was 4307 ms. Length: 50000000, IF executions: 25001582 Execution time was 4223 ms. Length: 50000000, IF executions: 25000694 Execution time was 4328 ms. Length: 50000000, IF executions: 25004766 Execution time was 4346 ms. ================================= Test mit rate = 1.0 Length: 50000000, IF executions: 50000000 Execution time was 3482 ms. Length: 50000000, IF executions: 50000000 Execution time was 3572 ms. Length: 50000000, IF executions: 50000000 Execution time was 3529 ms. Length: 50000000, IF executions: 50000000 Execution time was 3479 ms. Length: 50000000, IF executions: 50000000 Execution time was 3473 ms. The Code public ArrayList<Byte> list = new ArrayList<Byte>(); public final int LENGTH = 50000000; public PerformanceTest(){ byte[]arr = new byte[LENGTH]; Random random = new Random(); random.nextBytes(arr); for(byte b : arr) list.add(b); } public void run(double rate){ byte b = 0; int count = 0; for (int i = 0; i < LENGTH; i++) { if(getRate(rate)){ list.set(i, b); count++; } } System.out.println("Length: " + LENGTH + ", IF executions: " + count); } public boolean getRate(double rate){ return Math.random() < rate; } public static void main(String[] args) throws InterruptedException { PerformanceTest test = new PerformanceTest(); long start, end; System.out.println("Test mit rate = 0.5"); for (int i = 0; i < 5; i++) { start=System.currentTimeMillis(); test.run(0.5); end = System.currentTimeMillis(); System.out.println("Execution time was "+(end-start)+" ms."); Thread.sleep(500); } System.out.println("================================="); System.out.println("Test mit rate = 1.0"); for (int i = 0; i < 5; i++) { start=System.currentTimeMillis(); test.run(1.0); end = System.currentTimeMillis(); System.out.println("Execution time was "+(end-start)+" ms."); Thread.sleep(500); } }

    Read the article

  • Why is there a Null Pointer Exception in this Java Code?

    - by algorithmicCoder
    This code takes in users and movies from two separate files and computes a user score for a movie. When i run the code I get the following error: Exception in thread "main" java.lang.NullPointerException at RecommenderSystem.makeRecommendation(RecommenderSystem.java:75) at RecommenderSystem.main(RecommenderSystem.java:24) I believe the null pointer exception is due to an error in this particular class but I can't spot it....any thoughts? import java.io.*; import java.lang.Math; public class RecommenderSystem { private Movie[] m_movies; private User[] m_users; /** Parse the movies and users files, and then run queries against them. */ public static void main(String[] argv) throws FileNotFoundException, ParseError, RecommendationError { FileReader movies_fr = new FileReader("C:\\workspace\\Recommender\\src\\IMDBTop10.txt"); FileReader users_fr = new FileReader("C:\\workspace\\Recommender\\src\\IMDBTop10-users.txt"); MovieParser mp = new MovieParser(movies_fr); UserParser up = new UserParser(users_fr); Movie[] movies = mp.getMovies(); User[] users = up.getUsers(); RecommenderSystem rs = new RecommenderSystem(movies, users); System.out.println("Alice would rate \"The Shawshank Redemption\" with at least a " + rs.makeRecommendation("The Shawshank Redemption", "asmith")); System.out.println("Carol would rate \"The Dark Knight\" with at least a " + rs.makeRecommendation("The Dark Knight", "cd0")); } /** Instantiate a recommender system. * * @param movies An array of Movie that will be copied into m_movies. * @param users An array of User that will be copied into m_users. */ public RecommenderSystem(Movie[] movies, User[] users) throws RecommendationError { m_movies = movies; m_users = users; } /** Suggest what the user with "username" would rate "movieTitle". * * @param movieTitle The movie for which a recommendation is made. * @param username The user for whom the recommendation is made. */ public double makeRecommendation(String movieTitle, String username) throws RecommendationError { int userNumber; int movieNumber; int j=0; double weightAvNum =0; double weightAvDen=0; for (userNumber = 0; userNumber < m_users.length; ++userNumber) { if (m_users[userNumber].getUsername().equals(username)) { break; } } for (movieNumber = 0; movieNumber < m_movies.length; ++movieNumber) { if (m_movies[movieNumber].getTitle().equals(movieTitle)) { break; } } // Use the weighted average algorithm here (don't forget to check for // errors). while(j<m_users.length){ if(j!=userNumber){ weightAvNum = weightAvNum + (m_users[j].getRating(movieNumber)- m_users[j].getAverageRating())*(m_users[userNumber].similarityTo(m_users[j])); weightAvDen = weightAvDen + (m_users[userNumber].similarityTo(m_users[j])); } j++; } return (m_users[userNumber].getAverageRating()+ (weightAvNum/weightAvDen)); } } class RecommendationError extends Exception { /** An error for when something goes wrong in the recommendation process. * * @param s A string describing the error. */ public RecommendationError(String s) { super(s); } }

    Read the article

  • Why some pictures are are crooked aftes using my function?

    - by Miko Kronn
    struct BitmapDataAccessor { private readonly byte[] data; private readonly int[] rowStarts; public readonly int Height; public readonly int Width; public BitmapDataAccessor(byte[] data, int width, int height) { this.data = data; this.Height = height; this.Width = width; rowStarts = new int[height]; for (int y = 0; y < Height; y++) rowStarts[y] = y * width; } public byte this[int x, int y, int color] // Maybe use an enum with Red = 0, Green = 1, and Blue = 2 members? { get { return data[(rowStarts[y] + x) * 3 + color]; } set { data[(rowStarts[y] + x) * 3 + color] = value; } } public byte[] Data { get { return data; } } } public static byte[, ,] Bitmap2Byte(Bitmap obraz) { int h = obraz.Height; int w = obraz.Width; byte[, ,] wynik = new byte[w, h, 3]; BitmapData bd = obraz.LockBits(new Rectangle(0, 0, w, h), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb); int bytes = Math.Abs(bd.Stride) * h; byte[] rgbValues = new byte[bytes]; IntPtr ptr = bd.Scan0; System.Runtime.InteropServices.Marshal.Copy(ptr, rgbValues, 0, bytes); BitmapDataAccessor bda = new BitmapDataAccessor(rgbValues, w, h); for (int i = 0; i < h; i++) { for (int j = 0; j < w; j++) { wynik[j, i, 0] = bda[j, i, 2]; wynik[j, i, 1] = bda[j, i, 1]; wynik[j, i, 2] = bda[j, i, 0]; } } obraz.UnlockBits(bd); return wynik; } public static Bitmap Byte2Bitmap(byte[, ,] tablica) { if (tablica.GetLength(2) != 3) { throw new NieprawidlowyWymiarTablicyException(); } int w = tablica.GetLength(0); int h = tablica.GetLength(1); Bitmap obraz = new Bitmap(w, h, PixelFormat.Format24bppRgb); for (int i = 0; i < w; i++) { for (int j = 0; j < h; j++) { Color kol = Color.FromArgb(tablica[i, j, 0], tablica[i, j, 1], tablica[i, j, 2]); obraz.SetPixel(i, j, kol); } } return obraz; } Now, if I do: private void btnLoad_Click(object sender, EventArgs e) { if (dgOpenFile.ShowDialog() == DialogResult.OK) { try { Bitmap img = new Bitmap(dgOpenFile.FileName); byte[, ,] tab = Grafika.Bitmap2Byte(img); picture.Image = Grafika.Byte2Bitmap(tab); picture.Size = img.Size; } catch (Exception ex) { MessageBox.Show(ex.Message); } } } Most of pictures are handled correctly butsome not. Example of picture that doesn't work: It produce following result (this is only fragment of picture) : Why is that?

    Read the article

  • MySQL search for user and their roles

    - by Jenkz
    I am re-writing the SQL which lets a user search for any other user on our site and also shows their roles. An an example, roles can be "Writer", "Editor", "Publisher". Each role links a User to a Publication. Users can take multiple roles within multiple publications. Example table setup: "users" : user_id, firstname, lastname "publications" : publication_id, name "link_writers" : user_id, publication_id "link_editors" : user_id, publication_id Current psuedo SQL: SELECT * FROM ( (SELECT user_id FROM users WHERE firstname LIKE '%Jenkz%') UNION (SELECT user_id FROM users WHERE lastname LIKE '%Jenkz%') ) AS dt JOIN (ROLES STATEMENT) AS roles ON roles.user_id = dt.user_id At the moment my roles statement is: SELECT dt2.user_id, dt2.publication_id, dt.role FROM ( (SELECT 'writer' AS role, link_writers.user_id, link_writers.publication_id FROM link_writers) UNION (SELECT 'editor' AS role, link_editors.user_id, link_editors.publication_id FROM link_editors) ) AS dt2 The reason for wrapping the roles statement in UNION clauses is that some roles are more complex and require a table join to find the publication_id and user_id. As an example "publishers" might be linked accross two tables "link_publishers": user_id, publisher_group_id "link_publisher_groups": publisher_group_id, publication_id So in that instance, the query forming part of my UNION would be: SELECT 'publisher' AS role, link_publishers.user_id, link_publisher_groups.publication_id FROM link_publishers JOIN link_publisher_groups ON lpg.group_id = lp.group_id I'm pretty confident that my table setup is good (I was warned off the one-table-for-all system when researching the layout). My problem is that there are now 100,000 rows in the users table and upto 70,000 rows in each of the link tables. Initial lookup in the users table is fast, but the joining really slows things down. How can I only join on the relevant roles? -------------------------- EDIT ---------------------------------- Explain above (open in a new window to see full resolution). The bottom bit in red, is the "WHERE firstname LIKE '%Jenkz%'" the third row searches WHERE CONCAT(firstname, ' ', lastname) LIKE '%Jenkz%'. Hence the large row count, but I think this is unavoidable, unless there is a way to put an index accross concatenated fields? The green bit at the top just shows the total rows scanned from the ROLES STATEMENT. You can then see each individual UNION clause (#6 - #12) which all show a large number of rows. Some of the indexes are normal, some are unique. It seems that MySQL isn't optimizing to use the dt.user_id as a comparison for the internal of the UNION statements. Is there any way to force this behaviour? Please note that my real setup is not publications and writers but "webmasters", "players", "teams" etc.

    Read the article

  • WCF/REST Get image into picturebox?

    - by Garrith
    So I have wcf rest service which succesfuly runs from a console app, if I navigate to: http://localhost:8000/Service/picture/300/400 my image is displayed note the 300/400 sets the width and height of the image within the body of the html page. The code looks like this: namespace WcfServiceLibrary1 { [ServiceContract] public interface IReceiveData { [OperationContract] [WebInvoke(Method = "GET", BodyStyle = WebMessageBodyStyle.Wrapped, ResponseFormat = WebMessageFormat.Xml, UriTemplate = "picture/{width}/{height}")] Stream GetImage(string width, string height); } public class RawDataService : IReceiveData { public Stream GetImage(string width, string height) { int w, h; if (!Int32.TryParse(width, out w)) { w = 640; } // Handle error if (!Int32.TryParse(height, out h)) { h = 400; } Bitmap bitmap = new Bitmap(w, h); for (int i = 0; i < bitmap.Width; i++) { for (int j = 0; j < bitmap.Height; j++) { bitmap.SetPixel(i, j, (Math.Abs(i - j) < 2) ? Color.Blue : Color.Yellow); } } MemoryStream ms = new MemoryStream(); bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); ms.Position = 0; WebOperationContext.Current.OutgoingResponse.ContentType = "image/jpeg"; return ms; } } } What I want to do now is use a client application "my windows form app" and add that image into a picturebox. Im abit stuck as to how this can be achieved as I would like the width and height of the image from my wcf rest service to be set by the width and height of the picturebox. I have tryed this but on two of the lines have errors and im not even sure if it will work as the code for my wcf rest service seperates width and height with a "/" if you notice in the url. string uri = "http://localhost:8080/Service/picture"; private void button1_Click(object sender, EventArgs e) { StringBuilder sb = new StringBuilder(); sb.AppendLine("<picture>"); sb.AppendLine("<width>" + pictureBox1.Image.Width + "</width>"); // the url looks like this http://localhost:8080/Service/picture/300/400 when accessing the image so I am trying to set this here sb.AppendLine("<height>" + pictureBox1.Image.Height + "</height>"); sb.AppendLine("</picture>"); string picture = sb.ToString(); byte[] getimage = Encoding.UTF8.GetBytes(picture); // not sure this is right HttpWebRequest req = WebRequest.Create(uri); //cant convert webrequest to httpwebrequest req.Method = "GET"; req.ContentType = "image/jpg"; req.ContentLength = getimage.Length; MemoryStream reqStrm = req.GetRequestStream(); //cant convert IO stream to IO Memory stream reqStrm.Write(getimage, 0, getimage.Length); reqStrm.Close(); HttpWebResponse resp = req.GetResponse(); // cant convert web respone to httpwebresponse MessageBox.Show(resp.StatusDescription); pictureBox1.Image = Image.FromStream(reqStrm); reqStrm.Close(); resp.Close(); } So just wondering if some one could help me out with this futile attempt at adding a variable image size from my rest service to a picture box on button click. This is the host app aswell: namespace ConsoleApplication1 { class Program { static void Main(string[] args) { string baseAddress = "http://" + Environment.MachineName + ":8000/Service"; ServiceHost host = new ServiceHost(typeof(RawDataService), new Uri(baseAddress)); host.AddServiceEndpoint(typeof(IReceiveData), new WebHttpBinding(), "").Behaviors.Add(new WebHttpBehavior()); host.Open(); Console.WriteLine("Host opened"); Console.ReadLine();

    Read the article

  • Java template classes using generator or similar?

    - by Hugh Perkins
    Is there some library or generator that I can use to generate multiple templated java classes from a single template? Obviously Java does have a generics implementation itself, but since it uses type-erasure, there are lots of situations where it is less than adequate. For example, if I want to make a self-growing array like this: class EasyArray { T[] backingarray; } (where T is a primitive type), then this isn't possible. This is true for anything which needs an array, for example high-performance templated matrix and vector classes. It should probably be possible to write a code generator which takes a templated class and generates multiple instantiations, for different types, eg for 'double' and 'float' and 'int' and 'String'. Is there something that already exists that does this? Edit: note that using an array of Object is not what I'm looking for, since it's no longer an array of primitives. An array of primitives is very fast, and uses only as much space a sizeof(primitive) * length-of-array. An array of object is an array of pointers/references, that points to Double objects, or similar, which could be scattered all over the place in memory, require garbage collection, allocation, and imply a double-indirection for access. Edit2: good god, voted down for asking for something that probably doesn't currently exist, but is technically possible and feasible? Does that mean that people looking for ways to improve things have already left the java community? Edit3: Here is code to show the difference in performance between primitive and boxed arrays: int N = 10*1000*1000; double[]primArray = new double[N]; for( int i = 0; i < N; i++ ) { primArray[i] = 123.0; } Object[] objArray = new Double[N]; for( int i = 0; i < N; i++ ) { objArray[i] = 123.0; } tic(); primArray = new double[N]; for( int i = 0; i < N; i++ ) { primArray[i] = 123.0; } toc(); tic(); objArray = new Double[N]; for( int i = 0; i < N; i++ ) { objArray[i] = 123.0; } toc(); Results: double[] array: 148 ms Double[] array: 4614 ms Not even close!

    Read the article

  • pagerAnchorBuilder - trying to add classes

    - by Bert Murphy
    I'm using Cycle2 to build a carousel gallery and I've run into a little problem regarding styling the pager buttons. What I've gathered is that Cycle2 creates its own pager span tags for each slide which is a bummer becaus I've already styled my the sub-nav markup. This should be a minor issue as long as I can assign individual classes to the spans and change my css accordingly. However, I can't get this to work. TLDR: I was hoping that I could use pagerAnchorBuilder to create individual classes for each span. I can't. Help. The original markup (pre Cycle2) looks like the following: <div id ="sub-nav" class="sub-nav"> <ul> <li><a id="available" class="available" href="#"></a></li> <li><a id="reliable" class="reliable" href="#"></a></li> <li><a id="use" class="use" href="#"></a></li> <li><a id="reports" class="reports" href="#"></a></li> <li class="last"><a id="software" class="software" href="#"></a></li> </ul> </div> With Cycle2 it looks like this (note the addition of the span tags) <div id ="sub-nav" class="sub-nav"> <ul> <li><a id="available" class="available" href="#"></a></li> <li><a id="reliable" class="reliable" href="#"></a></li> <li><a id="use" class="use" href="#"></a></li> <li><a id="reports" class="reports" href="#"></a></li> <li class="last"><a id="software" class="software" href="#"></a></li> </ul> <span class="cycle-pager-active">•</span><span>•</span><span>•</span><span>•</span><span>•</span></nav> </div> Cycle2 $('#sliding-gallery ul').cycle({ fx: 'carousel', carouselVisible: 1, speed: 'fast', timeout: 10000, slides: '>li', next: '.next', prev: '.prev', pager: '.sub-nav', pagerAnchorBuilder: function(idx, slide) { return '.sub-nav span:eq(' + idx + ')'; } });

    Read the article

  • How to get selected category id after 1st page in pagination?

    - by Surjay
    //$id=$_REQUEST['category']; //$catid=mysql_escape_string($id); $catid = isset($_GET['category']) ? (int)$_GET['category'] : 0; $recordsPerPage =4; 0 // //default startup page $pageNum = 1; if(isset($_GET['p'])) { $pageNum = $_GET['p']; settype($pageNum, 'integer'); } $offset = ($pageNum - 1) * $recordsPerPage; //set the number of columns $columns = 1; //set the number of columns $columns = 1; $query = "SELECT temp_id, temp_img, temp_header, temp_resize, temp_small, temp_name, temp_type, cat_id, col_id, artist_id FROM templates where cat_id = '{$catid}' ORDER BY temp_id DESC LIMIT $offset, $recordsPerPage"; $result = mysql_query($query); //we add this line because we need to know the number of rows $num_rows = mysql_num_rows($result); echo ""; //changed this to a for loop so we can use the number of rows for($i = 0; $i < $num_rows; $i++) { while($row = mysql_fetch_array($result)){ if($i % $columns == 0) { //if there is no remainder, we want to start a new row echo ""; } echo ...........my data(s). if(($i % $columns) == ($columns - 1) || ($i + 1) == $num_rows) { echo ""; } } } echo ""; //} ? <div class="pagination"> <? $query = "SELECT COUNT( temp_id ) AS `temp_date` FROM `templates` where cat_id ='{$catid}'"; $result = mysql_query($query) or die('Mysql Err. 2'); $row = mysql_fetch_assoc($result); $numrows = $row['temp_date']; //$numrows = mysql_num_rows($result); $self = $_SERVER['PHP_SELF']; $maxPage = ceil($numrows/$recordsPerPage); $nav = ''; for($page = 1; $page <= $maxPage; $page++) { if ($page == $pageNum) { $nav .= "$page"; } else { $nav .= "$page"; } } if ($pageNum 1) { $page = $pageNum - 1; $prev = ""; $first = ""; } else { $prev = ' '; $first = ' '; } if ($pageNum < $maxPage) { $page = $pageNum + 1; $next = " "; $last = " "; } else { $next = ' '; $last = ' '; } echo " $first $prev $nav $next $last "; ? Here my ajax code: function GetXmlHttpObject(handler) { var objXMLHttp=null if (window.XMLHttpRequest) { objXMLHttp=new XMLHttpRequest() } else if (window.ActiveXObject) { objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP") } return objXMLHttp } function stateChanged() { if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete") { document.getElementById("txtResult").innerHTML=xmlHttp.responseText } else { //alert(xmlHttp.status); } } function htmlData(url, qStr) { if (url.length==0) { document.getElementById("txtResult").innerHTML=""; return; } xmlHttp=GetXmlHttpObject() if (xmlHttp==null) { alert ("Browser does not support HTTP Request"); return; } url=url+"?"+qStr; url=url+"&sid="+Math.random(); xmlHttp.onreadystatechange=stateChanged; xmlHttp.open("GET",url,true) ; xmlHttp.send(null); }

    Read the article

  • JPanel's child components paint/layout problem

    - by Tom Brito
    I'm having a problem that when my frame is shown (after a login dialog) the buttons are not on correct position, then in some miliseconds they go to the right position (the center of the panel with border layout). When I make a SSCCE, it works correct, but when I run my whole code I have this fast-miliseconds delay to the buttons to go to the correct place. Unfortunately, I can't post the whole code, but the method that shows the frame is: public void login(JComponent userView) { centerPanel.removeAll(); centerPanel.add(userView); centerPanel.revalidate(); centerPanel.repaint(); frame.setVisible(true); } What would cause this delay to the panel layout? (I'm running everything in the EDT) -- update In my machine, this SSCCE shows the layout problem in 2 of 10 times I run it: import java.awt.BorderLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; public class TEST { public static void main(String[] args) throws Exception { SwingUtilities.invokeAndWait(new Runnable() { @Override public void run() { System.out.println("Debug test..."); JPanel btnPnl = new JPanel(); btnPnl.add(new JButton("TEST")); JFrame f = new JFrame("TEST"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.getContentPane().setLayout(new BorderLayout()); f.getContentPane().add(btnPnl); f.pack(); f.setSize(800, 600); f.setVisible(true); System.out.println("End debug test!"); } }); } } The button first appers in the up-left, and then it goes to the center. Please, note that I'm understand, not just correct. Is it a java bug? --update OK, so the SSCCE don't show the problem with you that tried till now. Maybe it's my computer performance problem. But this don't answer the question, I still think Java Swing is creating new threads for make the layout behind the scenes.

    Read the article

  • prolog sets problem, stack overflow

    - by garm0nboz1a
    Hi. I'm gonna show some code and ask, what could be optimized and where am I sucked? sublist([], []). sublist([H | Tail1], [H | Tail2]) :- sublist(Tail1, Tail2). sublist(H, [_ | Tail]) :- sublist(H, Tail). less(X, X, _). less(X, Z, RelationList) :- member([X,Z], RelationList). less(X, Z, RelationList) :- member([X,Y], RelationList), less(Y, Z, RelationList), \+less(Z, X, RelationList). lessList(X, LessList, RelationList) :- findall(Y, less(X, Y, RelationList), List), list_to_set(List, L), sort(L, LessList), !. list_mltpl(List1, List2, List) :- findall(X, ( member(X, List1), member(X, List2)), List). chain([_], _). chain([H,T | Tail], RelationList) :- less(H, T, RelationList), chain([T|Tail], RelationList), !. have_inf(X1, X2, RelationList) :- lessList(X1, X1_cone, RelationList), lessList(X2, X2_cone, RelationList), list_mltpl(X1_cone, X2_cone, Cone), chain(Cone, RelationList), !. relations(List, E) :- findall([X1,X2], (member(X1, E), member(X2, E), X1 =\= X2), Relations), sublist(List, Relations). semilattice(List, E) :- forall( (member(X1, E), member(X2, E), X1 < X2), have_inf(X1, X2, List) ). main(E) :- relations(X, E), semilattice(X, E). I'm trying to model all possible graph sets of N elements. Predicate relations(List, E) connects list of possible graphs(List) and input set E. Then I'm describing semilattice predicate to check relations' List for some properties. So, what I have. 1) semilattice/2 is working fast and clear ?- semilattice([[1,3],[2,4],[3,5],[4,5]],[1,2,3,4,5]). true. ?- semilattice([[1,3],[1,4],[2,3],[2,4],[3,5],[4,5]],[1,2,3,4,5]). false. 2) relations/2 is working not well ?- findall(X, relations(X,[1,2,3,4]), List), length(List, Len), writeln(Len),fail. 4096 false. ?- findall(X, relations(X,[1,2,3,4,5]), List), length(List, Len), writeln(Len),fail. ERROR: Out of global stack ^ Exception: (11) setup_call_catcher_cleanup('$bags':'$new_findall_bag'(17852886), '$bags':fa_loop(_G263, user:relations(_G263, [1, 2, 3, 4|...]), 17852886, _G268, []), _G835, '$bags':'$destroy_findall_bag'(17852886)) ? abort % Execution Aborted 3) Mix of them to finding all possible semilattice does not work at all. ?- main([1,2]). ERROR: Out of local stack ^ Exception: (15) setup_call_catcher_cleanup('$bags':'$new_findall_bag'(17852886), '$bags':fa_loop(_G41, user:less(1, _G41, [[1, 2], [2, 1]]), 17852886, _G52, []), _G4767764, '$bags':'$destroy_findall_bag'(17852886)) ?

    Read the article

  • Securing paths in PHP

    - by tjm
    I'm writing some PHP which takes some paths to different content directories, and uses these to include various parts of pages later. I'm trying to ensure that the paths are as they seem, and none of them break the rules of the application. I have PRIVATEDIR which must lie above DOCUMENT_ROOT (aka) PUBLICDIR. CONTENTDIR which must lie within PRIVATEDIR and not go back below PUBLICDIR and some other *DIR's which must remain within CONTENTDIR. Currently I set up some defaults, and then override the ones the user specifies and then sanity check them with the following. private function __construct($options) { error_reporting(0); if(is_array($options)) { $this->opts = array_merge($this->opts, $options); } if($this->opts['STATUS']==='debug') { error_reporting(E_ALL | E_NOTICE | E_STRICT); } $this->opts['PUBLICDIR'] = realpath($_SERVER['DOCUMENT_ROOT']) .DIRECTORY_SEPARATOR; $this->opts['PRIVATEDIR'] = realpath($this->opts['PUBLICDIR'] .$this->opts['PRIVATEDIR']) .DIRECTORY_SEPARATOR; $this->opts['CONTENTDIR'] = realpath($this->opts['PRIVATEDIR'] .$this->opts['CONTENTDIR']) .DIRECTORY_SEPARATOR; $this->opts['CACHEDIR'] = realpath($this->opts['PRIVATEDIR'] .$this->opts['CACHEDIR']) .DIRECTORY_SEPARATOR; $this->opts['ERRORDIR'] = realpath($this->opts['CONTENTDIR'] .$this->opts['ERRORDIR']) .DIRECTORY_SEPARATOR; $this->opts['TEMPLATEDIR' = realpath($this->opts['CONTENTDIR'] .$this->opts['TEMPLATEDIR']) .DIRECTORY_SEPARATOR; // then here I have to check that PRIVATEDIR is above PUBLICDIR // and that all the rest remain within private dir and don't drop // down into (or below) PUBLICDIR again. And die with an error if // they don't conform. } The thing is this seems like a lot of work to do, especially as it must be run, every time a page is accessed, before I can do anything else, e.g check for a cached version of the page I'm serving. Part of me is thinking, since all of these paths are predefined by the maintainer of the site, they SHOULD be aware of what paths they are allowing access to and ensuring they are secure. But, I think I'm thinking that because currently I am said maintainer, and I KNOW my paths conform to the rules. That said, I do want to secure this thing from any accidental errors by future maintainers (and I bet, now I've said above "I KNOW...", probably from myself somewhere down the line). This just feels like a suboptimal solution. I wonder how fast this would really be and what you would suggest to improve it or as an alternative? Thanks.

    Read the article

  • Need help with 2 MySql Queries. Join vs Subqueries.

    - by BugBusterX
    I have 2 tables: user: id, name message: sender_id, receiver_id, message, read_at, created_at There are 2 results I need to retrieve and I'm trying to find the best solution. I have included queries that I'm using in the very end. I need to retrieve a list of users, and also with each user have information available whether there are any unread messages from each user (them as sender, me as receiver) and whether or not there are any read messages between us ( they send I'm receiver or I send they are receivers) I need Same as above, but only those members where there has been any messaging between us, sorted by unread first, then by last message received. Can you advise please? Should this be done with joins or subqueries? In first case I do not need the count, I just need to know whether or not there is at least one unread message. I'm posting code and my current queries, please have a look when you get a chance: BTW, everything is the way I want in fist query. My concern is: In second query I would like to order by messages.created_at, but I dont think I can do that with grouping? And also I dont know if this approach is the most optimized and fast. CREATE TABLE `user` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL, PRIMARY KEY (`id`) ) INSERT INTO `user` VALUES (1,'User 1'),(2,'User 2'),(3,'User 3'),(4,'User 4'),(5,'User 5'); CREATE TABLE `message` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `sender_id` bigint(20) DEFAULT NULL, `receiver_id` bigint(20) DEFAULT NULL, `message` text, `read_at` datetime DEFAULT NULL, `created_at` datetime NOT NULL, PRIMARY KEY (`id`) ) INSERT INTO `message` VALUES (1,3,1,'Messge',NULL,'2010-10-10 10:10:10'),(2,1,4,'Hey','2010-10-10 10:10:12','2010-10-10 10:10:11'),(3,4,1,'Hello','2010-10-10 10:10:19','2010-10-10 10:10:15'),(4,1,4,'Again','2010-10-10 10:10:25','2010-10-10 10:10:21'),(5,3,1,'Hiii',NULL,'2010-10-10 10:10:21'); SELECT u.*, m_new.id as have_new, m.id as have_any FROM user u LEFT JOIN message m_new ON (u.id = m_new.sender_id AND m_new.receiver_id = 1 AND m_new.read_at IS NULL) LEFT JOIN message m ON ((u.id = m.sender_id AND m.receiver_id = 1) OR (u.id = m.receiver_id AND m.sender_id = 1)) GROUP BY u.id SELECT u.*, m_new.id as have_new, m.id as have_any FROM user u LEFT JOIN message m_new ON (u.id = m_new.sender_id AND m_new.receiver_id = 1 AND m_new.read_at IS NULL) LEFT JOIN message m ON ((u.id = m.sender_id AND m.receiver_id = 1) OR (u.id = m.receiver_id AND m.sender_id = 1)) where m.id IS NOT NULL GROUP BY u.id

    Read the article

  • Calculating all distances between one point and a group of points efficiently in R

    - by dbarbosa
    Hi, First of all, I am new to R (I started yesterday). I have two groups of points, data and centers, the first one of size n and the second of size K (for instance, n = 3823 and K = 10), and for each i in the first set, I need to find j in the second with the minimum distance. My idea is simple: for each i, let dist[j] be the distance between i and j, I only need to use which.min(dist) to find what I am looking for. Each point is an array of 64 doubles, so > dim(data) [1] 3823 64 > dim(centers) [1] 10 64 I have tried with for (i in 1:n) { for (j in 1:K) { d[j] <- sqrt(sum((centers[j,] - data[i,])^2)) } S[i] <- which.min(d) } which is extremely slow (with n = 200, it takes more than 40s!!). The fastest solution that I wrote is distance <- function(point, group) { return(dist(t(array(c(point, t(group)), dim=c(ncol(group), 1+nrow(group)))))[1:nrow(group)]) } for (i in 1:n) { d <- distance(data[i,], centers) which.min(d) } Even if it does a lot of computation that I don't use (because dist(m) computes the distance between all rows of m), it is way more faster than the other one (can anyone explain why?), but it is not fast enough for what I need, because it will not be used only once. And also, the distance code is very ugly. I tried to replace it with distance <- function(point, group) { return (dist(rbind(point,group))[1:nrow(group)]) } but this seems to be twice slower. I also tried to use dist for each pair, but it is also slower. I don't know what to do now. It seems like I am doing something very wrong. Any idea on how to do this more efficiently? ps: I need this to implement k-means by hand (and I need to do it, it is part of an assignment). I believe I will only need Euclidian distance, but I am not yet sure, so I will prefer to have some code where the distance computation can be replaced easily. stats::kmeans do all computation in less than one second.

    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 | 335 336 337 338 339 340 341 342 343 344 345 346  | Next Page >