Search Results

Search found 12044 results on 482 pages for 'foreach loop'.

Page 312/482 | < Previous Page | 308 309 310 311 312 313 314 315 316 317 318 319  | Next Page >

  • sqrt(int_value + 0.0) ? The point?

    - by Earlz
    Hello, while doing some homework in my very strange C++ book, which I've been told before to throw away, had a very peculiar code segment. I know homework stuff always throws in extra "mystery" to try to confuse you like indenting 2 lines after a single-statement for-loop. But this one I'm confused on because it seems to serve some real-purpose. basically it is like this: int counter=10; ... if(pow(floor(sqrt(counter+0.0)),2) == counter) ... I'm interested in this part especially: sqrt(counter+0.0) Is there some purpose to the +0.0? Is this the poormans way of doing a static cast to a double? Does this avoid some compiler warning on some compiler I do not use? The entire program printed the exact same thing and compiled without warnings on g++ whenever I left out the +0.0 part. Maybe I'm not using a weird enough compiler?

    Read the article

  • Handling of data truncation (short reads/writes) in FUSE

    - by Vi
    I expect any good program should do all their reads and writes in a loop until all data written/read without relying that write will write everything (even with regular files). Am I right? Implemented simple FUSE filesystem which only allows reading and writing with small buffers, very often returning that it is written less bytes that in a buffer (using -o direct_io). Some programs work, some not (notably mountlo). Are them buggy or programs should not expect truncated writes and reads from the regular files? In general, are seekable file descriptors expected to truncate data like sockets and pipes?

    Read the article

  • exporting html table multi line columns to excel multi line cells

    - by Passat
    I have a html table in a view MVC4 that I am sending to excel as output. Inside the view page I have some columns that have multiple lines that are built with forloops within the HTML. What's the best way to add the or \r\n so that excel renders it correctly? I have a table and inside I build each row looping thru a recordset. In each row I also loop thru different recordsets to populate columns within each row so that some of the columns may contain more than one value and they should show in different lines in the table that will export to excel.

    Read the article

  • Teacher confused about MVC?

    - by Gideon
    I have an assignment to create a game in java using MVC as a pattern. The thing is that stuff I read about MVC aren't really what the teacher is telling me. What I read is that the Model are the information objects, they are manipulated by the controllers. So in a game the controller mutates the placement of the objects and check if there is any collision etc. What my teacher told me is that I should put everything that is universal to the platform in the models and the controllers should only tell the model which input is given. That means the game loop will be in a model class, but also collision checks etc. So what I get from his story is that the View is the screen, the Controller is the unput handeler, and the Model is the rest. Can someone point me in the right direction?

    Read the article

  • Reusing a vector in C++

    - by Bobby
    I have a vector declared as a global variable that I need to be able to reuse. For example, I am reading multiple files of data, parsing the data to create objects that are then stored in a vector. vector<Object> objVector(100); void main() { while(THERE_ARE_MORE_FILES_TO_READ) { // Pseudocode ReadFile(); ParseFileIntoVector(); ProcessObjectsInVector(); /* Here I want to 'reset' the vector to 100 empty objects again */ } } Can I reset the vector to be "vector objVector(100)" since it was initially allocated on the stack? If I do "objVector.clear()", it removes all 100 objects and I would have a vector with a size of 0. I need it to be a size of 100 at the start of every loop.

    Read the article

  • Generate matrix with value flags

    - by pagid
    I do have a solution for the following problem but it's quite ugly and it can most likely be done in a much shorter way. Would be great to get your help. My input looks like this: C1 C2 A B B D D C A D and my output should look like this: A B C D 1 1 0 0 0 1 0 1 0 0 1 1 1 0 0 1 My current solution is: index <- unique(unlist(input[,1:2])) output <- matrix(0,nrows=dim(input),ncols=length(index)) for(i in 1:dim(input)) { output[i, input[i,]$C1] <- 1 output[i, input[i,]$C2] <- 1 } Of course 4-5 lines is actually fine - but even as an R beginner this doesn't feel right to use a for loop. Besides that my actual data has much more than two columns, therefore this doesn't look nice in the end. How would I do that in a smarter way? Cheers

    Read the article

  • General suggestions for making R code faster? [closed]

    - by gsk3
    Questions come up fairly frequently about how to make R code faster. This is an attempt to provide a general framework for thinking about the problem. Questions of this nature seem to fall into one of a few categories: I have a loop and it's running slowly. I've heard that vectorization can speed things up. How do I vectorize it? I've vectorized and it's still running slowly. What do I do next? I'd like to speed up my code but it's running quickly enough already. What are the principles and specifics which can be used to make R code run faster?

    Read the article

  • Can't catch newConnection() signal from QTcpServer

    - by Bob
    I am trying to make a simple server thread in QT to accept a connection, however although the server is listening (I can connect with my test app) I can't get the newConnection() signal to be acted on. Any help as to what I'm missing here would be much appreciated! class CServerThread : public QThread { Q_OBJECT protected: void run(); private: QTcpServer* server; public slots: void AcceptConnection(); }; void CServerThread::run() { server = new QTcpServer; QObject::connect(server, SIGNAL(newConnection()), this, SLOT(AcceptConnection())); server-listen(QHostAddress::Any, 1000); // Any port in a storm exec(); // Start event loop } void CServerThread::AcceptConnection() { OutputDebugStringA("\n***** INCOMING CONNECTION"); // This is never called! }

    Read the article

  • getting the value of a filter at an arbitrary time

    - by Andiih
    Context: I'm trying to improve the values returned by the iPhone CLLocationManager, although this is a more generally applicable problem. The key is that CLLocationManger returns data on current velocity as and when it feels like it, rather than at a fixed sample rate. I'd like to use a feedback equation to improve accuracy v=(k*v)+(1-k)*currentVelocity where currentVelocity is the speed returned by didUpdateToLocation:fromLocation: and v is the output velocity (and also used for the feedback element). Because of the "as and when" nature of didUpdateToLocation:fromLocation: I could calculate the time interval since it was last called, and do something like for (i=0;i<timeintervalsincelastcalled;i++) v=(k*v)+(1-k)*currentVelocity which would work, but is wasteful of cycles. Especially as I probably want timeintervalsincelastcalled to be measured as 10ths of a second. Is there a way to solve this without the loop ? i.e. rework (integrate?) the formula so I put an interval into the equation and get the same answer as I would have by iteration ?

    Read the article

  • Write a recursive function in C that converts a number into a string

    - by user3501779
    I'm studying software engineering, and came across this exercise: it asks to write a recursive function in C language that receives a positive integer and an empty string, and "translates" the number into a string. Meaning that after calling the function, the string we sent would contain the number but as a string of its digits. I wrote this function, but when I tried printing the string, it did print the number I sent, but in reverse. This is the function: void strnum(int n, char *str) { if(n) { strnum(n/10, str+1); *str = n%10 + '0'; } } For example, I sent the number 123 on function call, and the output was 321 instead of 123. I also tried exchanging the two lines within the if statement, and it still does the same. I can't figure out what I did wrong. Can someone help please? NOTE: Use of while and for loop statements is not allowed for the exercise.

    Read the article

  • Basic QT Event handling / Threading questions ?

    - by umanga
    Greetings , I am new to QT (4.6) and have some basic questions regarding its event mechanism.I come from Swing background so I am trying to compare it with QT. 1) Does Event-processing-loop run in seperate thread? (like EventDispatch thread in Swing) ? 2) If we open several 'QMainWindow' do they run in several threads? 3) Whats the best way to run an intensive process in a seperate thread? (like SwingWorker in Swing ? ) 4) If intesive-process runs in a seperate thread ,is it possible to call UI methods like update(),repaint() from that process? thanks in advance.

    Read the article

  • From xcode not able to execute DISTINCT keyword for sqlite

    - by mac
    -(void) readProductsFromDatabase { // Setup the database object sqlite3 *database; // Init the animals Array products = [[NSMutableArray alloc] init]; // Open the database from the users filessytem if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) { NSLog(@"db opened"); // Setup the SQL Statement and compile it for faster access const char *sqlStatement = "SELECT DISTINCT productname FROM iphone "; sqlite3_stmt *compiledStatement; if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) { // Loop through the results and add them to the feeds array while(sqlite3_step(compiledStatement) == SQLITE_ROW) { NSLog(@"inside sqlite3 prepare"); // Read the data from the result row NSString *aName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)]; } } // Release the compiled statement from memory sqlite3_finalize(compiledStatement); } sqlite3_close(database); } My problem is const char *sqlStatement = "SELECT DISTINCT productname FROM iphone "; This line not executing ,i am using sqlite3, thanks in advance,

    Read the article

  • How can I use cURL to open multiple URLs simultaneously with PHP?

    - by Rob
    Here is my current code: $SQL = mysql_query("SELECT url FROM urls") or die(mysql_error()); //Query the urls table while($resultSet = mysql_fetch_array($SQL)){ //Put all the urls into one variable // Now for some cURL to run it. $ch = curl_init($resultSet['url']); //load the urls curl_setopt($ch, CURLOPT_TIMEOUT, 2); //No need to wait for it to load. Execute it and go. curl_exec($ch); //Execute curl_close($ch); //Close it off } //While loop I'm relatively new to cURL. By relatively new, I mean this is my first time using cURL. Currently it loads one for two seconds, then loads the next one for 2 seconds, then the next. however, I want to make it load ALL of them at the same time. I'm sure its possible, I'm just unsure as to how. If someone could point me in the right direction, I'd appreciate it.

    Read the article

  • Why is Postgres doing a Hash in this query?

    - by Claudiu
    I have two tables: A and P. I want to get information out of all rows in A whose id is in a temporary table I created, tmp_ids. However, there is additional information about A in the P table, foo, and I want to get this info as well. I have the following query: SELECT A.H_id AS hid, A.id AS aid, P.foo, A.pos, A.size FROM tmp_ids, P, A WHERE tmp_ids.id = A.H_id AND P.id = A.P_id I noticed it going slowly, and when I asked Postgres to explain, I noticed that it combines tmp_ids with an index on A I created for H_id with a nested loop. However, it hashes all of P before doing a Hash join with the result of the first merge. P is quite large and I think this is what's taking all the time. Why would it create a hash there? P.id is P's primary key, and A.P_id has an index of its own.

    Read the article

  • How to analyse Dalvik GC behaviour?

    - by HRJ
    I am developing an application on Android. It is a long running application that continuously processes sensor data. While running the application I see a lot of GC messages in the logcat; about one every second. This is most probably because of objects being created and immediately de-referenced in a loop. How do I find which objects are being created and released immediately? All the java heap analysis tools that I have tried(*) are bothered with the counts and sizes of objects on the heap. While they are useful, I am more interested in finding out the site where temporary short-lived objects get created the most. (*) I tried jcat and Eclipse MAT. I couldn't get hat to work on the Android heap-dumps; it complained of an unsupported dump file version.

    Read the article

  • How SqlDataAdapter works internally?

    - by tigrou
    I wonder how SqlDataAdapter works internally, especially when using UpdateCommand for updating a huge DataTable (since it's usually a lot faster that just sending sql statements from a loop). Here is some idea I have in mind : It creates a prepared sql statement (using SqlCommand.Prepare()) with CommandText filled and sql parameters initialized with correct sql types. Then, it loops on datarows that need to be updated, and for each record, it updates parameters values, and call SqlCommand.ExecuteNonQuery(). It creates a bunch of SqlCommand objects with everything filled inside (CommandText and sql parameters). Several SqlCommands at once are then batched to the server (depending of UpdateBatchSize). It uses some special, low level or undocumented sql driver instructions that allow to perform an update on several rows in a effecient way (rows to update would need to be provided using a special data format and a the same sql query (UpdateCommand here) would be executed against each of these rows).

    Read the article

  • javascript function call automatically on page onload instead on onclick

    - by user357134
    I am facing a very strange problem. I have javascript function in my aspx page that i call on the onclick event.but on one particular machine it always automatically called on body onload in infinite loop. Though I already remove all the caching and delte the history and temp files. This seems very strange to me .It works fine on all the machine excpt one. The machine have windows 7 and IE verison 8.0.7600.16385 Can some one please help me. Thanks in advance.

    Read the article

  • Is there a better way to do SELECT queries in MySQL and sort them in PHP than this way?

    - by Kent
    I am just learning PHP/MySQL, one this I am having to do a lot is displaying data that was previously inserted into the database out to the user's browser. So I am doing this: $select = mysql_query('SELECT * FROM pages'); while ($return = mysql_fetch_assoc($select)) { $title = $return['title']; $author = $return['author']; $content = $return['content']; } then I can use these variables through out the page. Now, doing it the above way isn't an issue when I only have 3 columns in a database but what if I am dealing with a huge database with many more columns. I have a nagging feeling that the pros do it in some more efficient way where they maybe loop through the table they are selecting from to find all columns it has and associate them with variables automatically. Is that the case? or is the above how you guys do it too?

    Read the article

  • Faster way to compare two sets of points in N-dimensional space?

    - by Amit
    List1 contains a high number (~7^10) of N-dimensional points (N <=10), List2 contains the same or fewer number of N-dimensional points (N <=10). My task is this: I want to check which point in List2 is closest (euclidean distance) to a point in List1 for every point in List1 and subsequently perform some operation on it. I have been doing it the simple- the nested loop way when I didn't have more than 50 points in List1, but with 7^10 points, this obviously takes up a lot of time. What is the fastest way to do this? Any concepts from Computational Geometry might help?

    Read the article

  • How to retrieve large data from oracle database using vbscript

    - by allenzzzxd
    Hi guys, I'm now working on vbscript to do some test. Actuelly, I want to retrieve a large amount of data from an oracle database, so I write the code like this: sql = "Select * from CORE_DB where MC = '" & mstr & "' " Set myrs = db_execute_query(curConnection, sql) Then I count the rows in myrs,there are 248 rows. So then I do a For loop to retrieve some fields of each row. For k = 0 To db_get_rows_count(myrs) But then I found that the content of the row k when k 133 was always equal to k = 133. So this makes an error. As I think, there may be a limit size of mrys ? Could anyone light me about this? Thanks a lot in advance

    Read the article

  • How to use data of one table in 'where' clause of another table?

    - by sahar
    hello, i need ur help guys..i m making website for 'home docor ideas'..i have a log in form(login-form.php) in which when 'log in' and 'password' is inserted,after verification through login-execute.php, redirected to viewOrder.php where user can view all of the orders ordered by clients.. all is fine up till here.. but what i want is,when user get logged in ,he view only that order which is ordered by him not all customer's orders.. two tables are there in database: members and order_insert.. in 'members' table, login and password is stored and in 'order_insert',orders of customers is stored.. codes of these three pages is as follows.. ......................... login-form.php ......................... <form id="loginForm" name="loginForm" method="post" action="login-exec.php"> <table width="300" border="0" align="center" cellpadding="2" cellspacing="0"> <tr> <td width="112"><b>Login</b></td> <td width="188"><input name="login" type="text" class="textfield" id="login" /></td> </tr> <tr> <td><b>Password</b></td> <td><input name="password" type="password" class="textfield" id="password" /></td> </tr> <tr> <td>&nbsp;</td> <td><input type="submit" name="Submit" value="Login" /></td> </tr> </table> </form> ......................... login-execute.php ......................... <?php //Start session session_start(); //Include database connection details require_once('config.php'); //Array to store validation errors $errmsg_arr = array(); //Validation error flag $errflag = false; //Connect to mysql server $link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD); if(!$link) { die('Failed to connect to server: ' . mysql_error()); } //Select database $db = mysql_select_db(DB_DATABASE); if(!$db) { die("Unable to select database"); } //Function to sanitize values received from the form. Prevents SQL injection function clean($str) { $str = @trim($str); if(get_magic_quotes_gpc()) { $str = stripslashes($str); } return mysql_real_escape_string($str); } //Sanitize the POST values $login = clean($_POST['login']); $password = clean($_POST['password']); //Input Validations if($login == '') { $errmsg_arr[] = 'Login ID missing'; $errflag = true; } if($password == '') { $errmsg_arr[] = 'Password missing'; $errflag = true; } //If there are input validations, redirect back to the login form if($errflag) { $_SESSION['ERRMSG_ARR'] = $errmsg_arr; session_write_close(); header("location: login-form.php"); exit(); } //Create query $qry="SELECT * FROM members WHERE login='$login' AND passwd='".md5($_POST['password'])."'"; $result=mysql_query($qry); //Check whether the query was successful or not if($result) { if(mysql_num_rows($result) == 1) { //Login Successful session_regenerate_id(); $member = mysql_fetch_assoc($result); $_SESSION['SESS_MEMBER_ID'] = $member['member_id']; $_SESSION['SESS_FIRST_NAME'] = $member['firstname']; $_SESSION['SESS_LAST_NAME'] = $member['lastname']; session_write_close(); header("location: viewOrder.php"); exit(); }else { //Login failed header("location: login-failed.php"); exit(); } }else { die("Query failed"); } ?> ............................. viewOrder.php .............................. <html> <body bgcolor="#FFFFFF" > <? $host="localhost"; // Host name $username="root"; // Mysql username $password=""; // Mysql password $db_name="mydatabase"; // Database name $tbl_name="order_insert"; // Table name $tbl_name2="members"; // connect to server and databases mysql_connect("$host", "$username", "$password")or die("cannot connect"); mysql_select_db("$db_name")or die("cannot select DB"); $result = mysql_query("SELECT * FROM $tbl_name "); print "<center>"; $output .= "<table width=1100 border=1 bordercolor=black>"; $output .= "<tr align=center><td>ID</td><td>First Name</td><td>Last Name</td><td>E Mail</td><td> City </td><td> Country </td><td> Phone</td><td>Decoration Type</td><td>Service Description</td><td>Budget</td><td>Update</td><td>Delete</td></tr>"; $output .= "<th></th><th></th>"; $output .= "</tr>\n\n"; while ($row = mysql_fetch_assoc($result)){ $output .= "<tr>\n"; foreach ($row as $col=>$val){ $output .= " <td>$val</td>\n"; } // end foreach $keyVal = $row["id"]; $output .= "<td><a href='update.php?ID=$row[orderId]' >Update </a></td>"; $output .= "<td><a href='delete.php?ID=$row[orderId]' >Delete </a></td>"; $output .= "</tr>\n\n"; }// end while $output .= "</table></center>"; print "$output"; ?>&nbsp;&nbsp;&nbsp;<br> <br> <center><table > <tr><td> <form action="home.php"><font color="#FF0000"><input type="submit" name="btn" style="color:#CC0000" value="<--Back" ></font></form></td></tr></table></center> </body> </html> ..... your help and suggestions will be appreciated

    Read the article

  • C++: FFMPEG and SDL resources

    - by advs89
    I'm looking for resources (preferably books, but websites are fine too) for using FFMPEG and/or SDL with C++. Stuff I'd like to be able to do (eventually): Decode and play videos in realtime to a QT widget (the QT part isn't a problem) Overlay text and images on the video (in realtime) Loop video Cross-fade from one video to another (in realtime) Some kind of DVD functionality LIVE sources? (i.e. webcam, stream, etc.) So far I've looked at (and consider helpful) the following resources: FFMPEG and SDL Tutorial by Dranger (extremely helpful) StackOverflow: ffmpeg C API documentation/tutorial (not a duplicate, btw) Sample code bundled with FFMPEG libraries (I'll try and update this list with anything helpful below) Thanks for any help... Also: Operating System is Windows (but maybe one day cross-platform) Also 2: Resources using alternatives are welcome too... i.e. DirectShow, VFW, etc.

    Read the article

  • Display PHP Query Array in the table

    - by Jerry
    Hi all I would like to display my Query from Mysql on the table. However, my data is like this: Array([0]=>data1, [1]=>data2, [2]=>data3,[3]=>data4,[4]=>pic1,[5]=>pic2,[6]=>pic3,[7]=>pic4); I want to display my table as |data1 | data2 |data3 |data4 |pic1 | pic2 |pic3 |pic4 I know how to display the data in the single ling like td or tr but not sure how to do tr and td on the same loop. Any helps? Thanks in advance! while($query=mysql_fetch_array($dataQuery)){ //not sure what to do here. }

    Read the article

  • How to define a function which repeats itself when passed an argument

    - by ~unutbu
    Is there an easy way to define a function which repeats itself when passed an argument? For example, I've defined the following function (defun swap-sign () (interactive) (search-forward-regexp "[+-]") (if (equal (match-string 0) "-") (replace-match "+") (replace-match "-")) ) I'd like C-u swap-sign to call swap-sign four times. I've tried (defun swap-sign (&optional num) (interactive) (let ((counter 0) (num (if num (string-to-number num) 0))) (while (<= counter num) (search-forward-regexp "[+-]") (if (equal (match-string 0) "-") (replace-match "+") (replace-match "-")) (setq counter (1+ counter))))) but C-u swap-sign still only runs swap-sign (or perhaps more precisely, the body of the while-loop) once. I'm guessing it is because if num is not the right way to test if num is an empty string. Am I on the right track, or is there a better/easier way to extend swap-sign?

    Read the article

  • Construct Numpy index given list of starting and ending positions

    - by Abiel
    I have two identically-sized numpy.array objects (both one-dimensional), one of which contains a list of starting index positions, and the other of which contains a list of ending index positions (alternatively you could say I have a list of starting positions and window lengths). In case it matters, the slices formed by the starting and ending positions are guaranteed to be non-overlapping. I am trying to figure out how to use these starting and ending positions to form an index for another array object, without having to use a loop. For example: import numpy as np start = np.array([1,7,20]) end = np.array([3,10,25]) Want to reference somearray[1,2,7,8,9,20,21,22,23,24])

    Read the article

< Previous Page | 308 309 310 311 312 313 314 315 316 317 318 319  | Next Page >