Search Results

Search found 15104 results on 605 pages for 'multidimensional array'.

Page 21/605 | < Previous Page | 17 18 19 20 21 22 23 24 25 26 27 28  | Next Page >

  • Why does Python array moduel handle strings and lists differently?

    - by Casey
    I'm having trouble understanding the result of the following statements: >>> from array import array >>> array('L',[0xff,0xff,0xff,0xff]) array('L', [255L, 255L, 255L, 255L]) >>> from array import array >>> array('L','\xff\xff\xff\xff') Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: string length not a multiple of item size

    Read the article

  • Only compiles as an array of pointers, not array of arrays

    - by Dustin
    Suppose I define two arrays, each of which have 2 elements (for theoretical purposes): char const *arr1[] = { "i", "j" }; char const *arr2[] = { "m", "n" }; Is there a way to define a multidimensional array that contains these two arrays as elements? I was thinking of something like the following, but my compiler displays warnings about incompatible types: char const *combine[][2] = { arr1, arr2 }; The only way it would compile was to make the compiler treat the arrays as pointers: char const *const *combine[] = { arr1, arr2 }; Is that really the only way to do it or can I preserve the type somehow (in C++, the runtime type information would know it is an array) and treat combine as a multidimensional array? I realise it works because an array name is a const pointer, but I'm just wondering if there is a way to do what I'm asking in standard C/C++ rather than relying on compiler extensions. Perhaps I've gotten a bit too used to Python's lists where I could just throw anything in them...

    Read the article

  • Array not showing in Jlist but filled in console

    - by OVERTONE
    Hey there. been a busy debugger today. ill give ths short version. ive made an array list that takes names from a database. then i put the contents of the arraylist into an array of strings. now i want too display the arrays contents in a JList. the weird thing is it was working earlier. and ive two methods. ones just a little practice too make sure i was adding to the Jlist correctly. so heres the key codes. this is the layout of my code. variables constructor methods in my variables i have these 3 defined String[] contactListNames = new String[5]; ArrayList<String> rowNames = new ArrayList<String>(); JList contactList = new JList(contactListNames); simple enough. in my constructor i have them again. contactListNames = new String[5]; contactList = new JList(contactListNames); //i dont have the array list defined though. printSqlDetails(); // the prinSqldetails was too make sure that the connectionw as alright. and its working fine. fillContactList(); // this is the one thats causing me grief. its where all the work happens. // fillContactListTest(); // this was the tester that makes sure its adding to the list alright. heres the code for fillContactListTest() public void fillContactListTest() { for(int i = 0;i<3;i++) { try { String contact; System.out.println(" please fill the list at index "+ i); Scanner in = new Scanner(System.in); contact = in.next(); contactListNames[i] = contact; in.nextLine(); } catch(Exception e) { e.printStackTrace(); } } } heres the main one thats supposed too work. public void fillContactList() { int i =0; createConnection(); ArrayList<String> rowNames = new ArrayList<String>(); try { Statement stmt = conn.createStatement(); ResultSet namesList = stmt.executeQuery("SELECT name FROM Users"); try { while (namesList.next()) { rowNames.add(namesList.getString(1)); contactListNames =(String[])rowNames.toArray(new String[rowNames.size()]); // this used to print out contents of array list // System.out.println("" + rowNames); while(i<contactListNames.length) { System.out.println(" " + contactListNames[i]); i++; } } } catch(SQLException q) { q.printStackTrace(); } conn.commit(); stmt.close(); conn.close(); } catch(SQLException e) { e.printStackTrace(); } } i really need help here. im at my wits end. i just cant see why the first method would add to the JList no problem. but the second one wont. both the contactListNames array and array list can print fine and have the names in them. but i must be transfering them too the jlist wrong. please help p.s im aware this is long. but trust me its the short version.

    Read the article

  • Warning: array_multisort() [function.array-multisort]: Argument #1 is expected to be an array or a

    - by johnny
    Hi, the following code produces the error in the title. I've tried to google it, but all I got were pages who got the same error (and not an explanation thereof). This isn't really a problem since it's actually working and cancelling the error out with the @ works out just fine. Though I'm still wondering why I haven't been able to execute array_multisort just once without getting this error. public function getMostRelevant(){ list($occurrences, $keywords) = $this->occurr_keyw_array; array_multisort($occurrences, SORT_DESC, SORT_NUMERIC, $keywords); $return_array = array( array($occurrences[0], $keywords[0]), array($occurrences[1], $keywords[1]), array($occurrences[2], $keywords[2]) ); return $return_array; }

    Read the article

  • append a numpy array to a numpy array

    - by Fraz
    I just started programming in python and am very new to numpy packages.. so still trying to get a hang of it. I have a an numpy_array so something like [ a b c] And then I want to append it into anotehr numpyarray (Just like we create a list of lists) How do we create an array of numpy arrays containing numpy arrays I tried to do the following without any luck >>> M = np.array([]) >>> M array([], dtype=float64) >>> M.append(a,axis=0) Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'numpy.ndarray' object has no attribute 'append' >>> a array([1, 2, 3])

    Read the article

  • Array of ArrayList Java

    - by David Bobo
    Hi, I am creating an PriorityQueue with multiple queues. I am using an Array to store the multiple ArrayLists that make up my different PriorityQueues. Here is what I have for my constructor so far: ArrayList<ProcessRecord> pq; ArrayList[] arrayQ; MultiList(){ arrayQ = new ArrayList[9]; pq = new ArrayList<ProcessRecord>(); } The problem comes when I am trying to get the size of the entire array, that is the sum of the sizes of each ArrayList in the array. public int getSize(){ int size = 0; for(int i = 1; i <=9; i++){ size = size + this.arrayQ[i].size(); } return size; } is not seeming to work. Am I declaring the Array of ArrayList correctly? I keep getting an error saying that this.arrayQ[i].size() is not a method. (the .size() being the problem) Thanks for any help! David

    Read the article

  • jquery add to an array on click?

    - by KittyYoung
    I'm confused regarding each() and .each()... I think I need to use both, but I'm not sure how... Basically, I have a series of checkboxes and when they're checked, I want to get the id of the closest table row and add it to an array that I can then serialize and pass to a function. So, the html looks like this: <tr id="t1"><td><input type="checkbox" name="did[]" value="232" class="bd" /></td></tr> <tr id="t2"><td><input type="checkbox" name="did[]" value="234" class="bd" /></td></tr> <tr id="t3"><td><input type="checkbox" name="did[]" value="676" class="bd" /></td></tr> <tr><td><button id="tsid" name="tsid" type="button">Send</button></td></tr> And, when (and if) the checkbox is selected, I want to get the closest tr id and store it in an array: var trids = [] And then serialize the input data and the trids array... So far, I only have this: $('#tsid').click(function() { //meant to get the values of the selected checkboxes var myData = $('input[name=did[]]').serialize(); //meant to find and store the closest tr ids in an array... $('.bd').each(function() { var trids = $(this).closest("tr").get(0); //and now I'm lost... }); }

    Read the article

  • AS3: Array of objects parsed from XML remains with zero length

    - by Joel Alejandro
    I'm trying to parse an XML file and create an object array from its data. The data is converted to MediaAlbum classes (class of my own). The XML is parsed correctly and the object is loaded, but when I instantiate it, the Albums array is of zero length, even when the data is loaded correctly. I don't really know what the problem could be... any hints? import Nem.Media.*; var mg:MediaGallery = new MediaGallery("test.xml"); trace(mg.Albums.length); MediaGallery class: package Nem.Media { import flash.net.URLRequest; import flash.net.URLLoader; import flash.events.*; public class MediaGallery { private var jsonGalleryData:Object; public var Albums:Array = new Array(); public function MediaGallery(xmlSource:String) { var loader:URLLoader = new URLLoader(); loader.load(new URLRequest(xmlSource)); loader.addEventListener(Event.COMPLETE, loadGalleries); } public function loadGalleries(e:Event):void { var xmlData:XML = new XML(e.target.data); var album; for each (album in xmlData.albums) { Albums.push(new MediaAlbum(album.attribute("name"), album.photos)); } } } } XML test source: <gallery <albums <album name="Fútbol 9" <photos <photo width="600" height="400" filename="foto1.jpg" / <photo width="600" height="400" filename="foto2.jpg" / <photo width="600" height="400" filename="foto3.jpg" / </photos </album <album name="Fútbol 8" <photos <photo width="600" height="400" filename="foto4.jpg" / <photo width="600" height="400" filename="foto5.jpg" / <photo width="600" height="400" filename="foto6.jpg" / </photos </album </albums </gallery

    Read the article

  • How to print a Perl 2-dimensional array?

    - by Matt Pascoe
    I am trying to write a simple Perl script that reads a *.csv, places the rows of the *.csv file in a two dimensional array, and then prints on item out of the array and then prints a row of the array. #!/usr/bin/perl use strict; use warnings; open(CSV, $ARGV[0]) || die("Cannot open the $ARGV[0] file: $!"); my @row; my @table; while(<CSV>) { @row = split(/\s*,\s*/, $_); push(@table, @row); } close CSV || die $!; foreach my $element ( @{ $table[0] } ) { print $element, "\n"; } print "$table[0][1]\n"; When I run this script I receive the following error and nothing prints: Can't use string ("1") as an ARRAY ref while "strict refs" in use at ./scripts.pl line 16. I have looked in a number of other forums and am still not sure how to fix this issue. Can anyone help me fix this script?

    Read the article

  • How do I set an array in one class with another array in another class

    - by Stef
    I've populated and array with data like this in one class... PowerClass.h NSMutableArray pickerArray; @property (nonatomic, retain) NSMutableArray pickerArray; - PowerClass.m @synthesize pickerArray; @implementation NSMutableArray *array = [[NSArray alloc] initWithObjects:@"stef", @"steve", @"baddamans", @"jonny", nil]; pickerArray = [NSMutableArray arrayWithArray:array]; And I'm trying to set the Array in another class WeekClass.h PowerClass *powerClass; NSMutableArray *pickerData; @property (nonatomic, retain) NSMutableArray pickerData; @property (nonatomic, retain) PowerClass *powerClass; WeekClass.m @implementation pickerData = [NSMutableArray arrayWithArray:powerClass.pickerArray]; I have no errors or warnings. It just crashes. The NSLog says that the powerClass.pickerArray is NULL. Please help point me in the right direction.

    Read the article

  • How to delete duplicate vectors within a multidimensional vector?

    - by David
    I have a vector of vectors: vector< vector<int> > BigVec; It contains an arbitrary number of vectors, each of an arbitrary size. I want to delete not duplicate elements of each vector, but any vectors that are the exact same as another. I don't need to preserve the order of the vectors so I can sort etc.. It should be a really simple problem to solve but I'm new to this, my (not-working) best effort: for (int i = 0; i < BigVec.size(); i++) { for (int j = 1; j < BigVec.size() ; j++ ) { if (BigVec[i][0] == BigVec [j][i]); { BigVec.erase(BigVec.begin() + j); i = 0; // because i get the impression deleting a j = 1; // vector messes up a simple iteration through } } } I think there might be a solution using Unique(), but I can't get that to work either.

    Read the article

  • Double associative array or indexed + associative array

    - by clover
    I'm undecided what's the best-practice approach for what I'm trying to do. I'm trying to enter data into an array where the data will look like this: apple color: red price: 2 orange color: orange price: 3 banana color: yellow price: 2 pineapple color: yellow price: 5 When I get input, let's say green apple (notice it's a combo of color + name of fruit), I'm going to check if the name of fruit part exists in the array and display its data (if it exists). What's the right way to compose those arrays? How would I do an indexed array containing an associative array? (or would this be better as 2 nested associative arrays, I'm guessing not)

    Read the article

  • Performance question: Inverting an array of pointers in-place vs array of values

    - by Anders
    The background for asking this question is that I am solving a linearized equation system (Ax=b), where A is a matrix (typically of dimension less than 100x100) and x and b are vectors. I am using a direct method, meaning that I first invert A, then find the solution by x=A^(-1)b. This step is repated in an iterative process until convergence. The way I'm doing it now, using a matrix library (MTL4): For every iteration I copy all coeffiecients of A (values) in to the matrix object, then invert. This the easiest and safest option. Using an array of pointers instead: For my particular case, the coefficients of A happen to be updated between each iteration. These coefficients are stored in different variables (some are arrays, some are not). Would there be a potential for performance gain if I set up A as an array containing pointers to these coefficient variables, then inverting A in-place? The nice thing about the last option is that once I have set up the pointers in A before the first iteration, I would not need to copy any values between successive iterations. The values which are pointed to in A would automatically be updated between iterations. So the performance question boils down to this, as I see it: - The matrix inversion process takes roughly the same amount of time, assuming de-referencing of pointers is non-expensive. - The array of pointers does not need the extra memory for matrix A containing values. - The array of pointers option does not have to copy all NxN values of A between each iteration. - The values that are pointed to the array of pointers option are generally NOT ordered in memory. Hopefully, all values lie relatively close in memory, but *A[0][1] is generally not next to *A[0][0] etc. Any comments to this? Will the last remark affect performance negatively, thus weighing up for the positive performance effects?

    Read the article

  • How do I name an array key with a key inside the array

    - by Confused
    I have some data, yes, data. This data came from a MySQL query and it will always contain 4 items, always. I want to cache that data in an array table for use later within a web page but I want to keep the keys from the query and separate out each grouping within a multidimensional array. However to save time iterating through the array each time I want to find a given group of data, I want to call the keys of the first array the same as the ID key which is always the first key within each four items. At the minute I'm using this code: function mysql_fetch_full_result_array($result) { $table_result=array(); $r=0; while($row = mysql_fetch_assoc($result)){ $arr_row=array(); $c=0; while ($c < mysql_num_fields($result)) { $col = mysql_fetch_field($result, $c); $arr_row[$col -> name] = $row[$col -> name]; $c++; } $table_result[$r] = $arr_row; $r++; } return $table_result; } I'm currently testing this using 3 unique users, so I'm getting three rows back from the query and the data from this function ends up in the format: [0]=> . . [id] => 1 . . [name] => random name . . [tel] => random tel . . [post] => post code data [1]=> . . [id] => 34 . . [name] => random name . . [tel] => random tel . . [post] => post code data [2]=> . . [id] => 56 . . [name] => random name . . [tel] => random tel . . [post] => post code data So how do I alter the code to instead of the keys [0], [1], [2] give me the output: [1]=> . . [id] => 1 . . [name] => random name . . [tel] => random tel . . [post] => post code data [34]=> . . [id] => 34 . . [name] => random name . . [tel] => random tel . . [post] => post code data [56]=> . . [id] => 56 . . [name] => random name . . [tel] => random tel . . [post] => post code data I don't mind if the main array keys are strings of numbers rather than numbers but I'm a bit stuck, I tried changing the $table_result[$r] = $arr_row; part to read $table_result[$result['id']] = $arr_row; but that just outputs an array of one person. I know I need another loop but I'm struggling to work out how to write it.

    Read the article

  • Returning the element number of the longest string in an array

    - by JohnRoberts
    I'm trying to get the longestS method to take the user-inputted array of strings, then return the element number of the longest string in that array. I got it to the point where I was able to return the number of chars in the longest string, but I don't believe that will work for what I need. My problem is that I keep getting incompatible type errors when trying to figure this out. I don't understand the whole data type thing with strings yet. It's confusing me how I go about return a number of the array yet the array is of strings. The main method is fine, I got stuck on the ???? part. { public static void main(String [] args) { Scanner inp = new Scanner( System.in ); String [] responseArr= new String[4]; for (int i=0; i<4; i++) { System.out.println("Enter string "+(i+1)); responseArr[i] = inp.nextLine(); } int highest=longestS(responseArr); } public static int longestS(String[] values) { int largest=0 for( int i = 1; i < values.length; i++ ) { if ( ????? ) } return largest; } }

    Read the article

  • Merging multiple array then sorting by array value count

    - by Sofyan
    Hi, Please help me, i need to merge multiple arrays then sorting it by array value count. Below is the problem: $array1 = array("abc", "def", "ghi", "jkl", "mno"); $array2 = array("mno", "jkl", "mno", "ghi", "pqr", "stu"); $array3 = array_merge($array1, $array2); $array4 = ??? print_r($array4); I want the returns of $array4 like this: Array ( [0] => mno [1] => ghi [2] => jkl [3] => abc [4] => def [5] => pqr [6] => stu )

    Read the article

  • array_splice() - Numerical Offsets of Associative Arrays

    - by Alix Axel
    I'm trying to do something but I can't find any solution, I'm also having some trouble putting it into works so here is a sample code, maybe it'll be enough to demonstrate what I'm aiming for: $input = array ( 'who' => 'me', 'what' => 'car', 'more' => 'car', 'when' => 'today', ); Now, I want to use array_splice() to remove (and return) one element from the array: $spliced = key(array_splice($input, 2, 1)); // I'm only interested in the key... The above will remove and return 1 element (third argument) from $input (first argument), at offset 2 (second argument), so $spliced will hold the value more. I'll be iterating over $input with a foreach loop, I know the key to be spliced but the problem is I don't know its numerical offset and since array_splice only accepts integers I don't know what to do. A very dull example: $result = array(); foreach ($input as $key => $value) { if ($key == 'more') { // Remove the index "more" from $input and add it to $result. $result[] = key(array_splice($input, 2 /* How do I know its 2? */, 1)); } } I first though of using array_search() but it's pointless since it'll return the associative index.... How do I determine the numerical offset of a associative index?

    Read the article

  • looping through JSON array

    - by Phil Jackson
    Hi all. I have recently posted another question which straight away users pointed me in the right direction. $.ajax({ type: 'POST', url: './', data: 'token=' + token + '&re=8', cache: false, timeout: 5000, success: function(html){ auth(html); var JSON_array = eval(html); alert(JSON_array[0].username); } }); this returns the data correctly but I want to perform a kind of 'foreach'. the array contains data about multiple incoming and outgoing Instant Messages. So if a user is talking to more than one person at a time i need to loop through. the array's structure is as follows. Array ( [0] => Array ( [username] => Emmalene [contents] => <ul><li class="name">ACTwebDesigns</li><li class="speech">helllllllo</li></ul> <ul><li class="name">ACTwebDesigns</li><li class="speech">sds</li></ul> <ul><li class="name">ACTwebDesigns</li><li class="speech">Sponge</li><li class="speech">dick</li></ul> <ul><li class="name">ACTwebDesigns</li><li class="speech">arghh</li></ul> ) ) any help very much appreciated.

    Read the article

  • PHP Array - How to loop through an array

    - by Homer_J
    Hi My array is as follows: Array ( [questions] => q1 [qnum] => 1 [qtext] => I love crisps [page] => 1 ) Array ( [questions] => q2 [qnum] => 2 [qtext] => I love chocolate [page] => 1 ) All I would like to do is print the contents of the array in a loop, so it looks something like: q1 1 I love crisps q2 2 I love chocolate If anyone could supply the PHP and HTML code, that would be great, thanks. Homer.

    Read the article

  • Placing PHP array values into a javascript array?

    - by Michael Harringon
    Is these a way i can loop through a PHP array and have the data outputted into a JavaScript array? For example, the JS script below will not work var mon_Loop = <?php echo $rowCount_Mon ?>; var mon_Events = new Array(); for(i = 0; i < mon_Loop; i++) { mon_Events[i] = <?php $divMon[i] ?> } I Know its because the "i" is not a php variable so therefore invalid inside the php section, but its just an way to show what i would like to achieve. The $rowCount variable count the number of rows and is then used to for the loop. Lets say, for example that I want to place the contents of the PHP array "$divMon[0]" into the javascript array mon_Events[0]. I know that i can do it manually, like below mon_Events[0] = <?php echo $divMon[0] ?> But i have lots of these and therefore need the loop, Is there some JS or PHP that could do this? Cheers.

    Read the article

  • Creating a Ruby method that pads an Array

    - by CJ Johnson
    I'm working on creating a method that pads an array, and accepts 1. a desired value and 2. an optional string/integer value. Desired_size reflects the desired number of elements in the array. If a string/integer is passed in as the second value, this value is used to pad the array with extra elements. I understand there is a 'fill' method that can shortcut this - but that would be cheating for the homework I'm doing. The issue: no matter what I do, only the original array is returned. I started here: class Array def pad(desired_size, value = nil) desired_size >= self.length ? return self : (desired_size - self.length).times.do { |x| self << value } end end test_array = [1, 2, 3] test_array.pad(5) From what I researched the issue seemed to be around trying to alter self's array, so I learned about .inject and gave that a whirl: class Array def pad(desired_size, value = nil) if desired_size >= self.length return self else (desired_size - self.length).times.inject { |array, x| array << value } return array end end end test_array = [1, 2, 3] test_array.pad(5) The interwebs tell me the problem might be with any reference to self so I wiped that out altogether: class Array def pad(desired_size, value = nil) array = [] self.each { |x| array << x } if desired_size >= array.length return array else (desired_size - array.length).times.inject { |array, x| array << value } return array end end end test_array = [1, 2, 3] test_array.pad(5) I'm very new to classes and still trying to learn about them. Maybe I'm not even testing them the right way with my test_array? Otherwise, I think the issue is I get the method to recognize the desired_size value that's being passed in. I don't know where to go next. Any advice would be appreciated. Thanks in advance for your time.

    Read the article

  • How to write a good PHP database insert using an associative array

    - by Tom
    In PHP, I want to insert into a database using data contained in a associative array of field/value pairs. Example: $_fields = array('field1'=>'value1','field2'=>'value2','field3'=>'value3'); The resulting SQL insert should look as follows: INSERT INTO table (field1,field2,field3) VALUES ('value1','value2','value3'); I have come up with the following PHP one-liner: mysql_query("INSERT INTO table (".implode(',',array_keys($_fields)).") VALUES (".implode(',',array_values($_fields)).")"); It separates the keys and values of the the associative array and implodes to generate a comma-separated string . The problem is that it does not escape or quote the values that were inserted into the database. To illustrate the danger, Imagine if $_fields contained the following: $_fields = array('field1'=>"naustyvalue); drop table members; --"); The following SQL would be generated: INSERT INTO table (field1) VALUES (naustyvalue); drop table members; --; Luckily, multiple queries are not supported, nevertheless quoting and escaping are essential to prevent SQL injection vulnerabilities. How do you write your PHP Mysql Inserts? Note: PDO or mysqli prepared queries aren't currently an option for me because the codebase already uses mysql extensively - a change is planned but it'd take alot of resources to convert?

    Read the article

< Previous Page | 17 18 19 20 21 22 23 24 25 26 27 28  | Next Page >