Search Results

Search found 1698 results on 68 pages for 'loops'.

Page 9/68 | < Previous Page | 5 6 7 8 9 10 11 12 13 14 15 16  | Next Page >

  • Alternatives to javascript function-based iteration (e.g. jQuery.each())

    - by Colin
    I've been watching Google Tech Talks' Speed Up Your Javascript and in talking about loops, the speaker mentions to stay away from function-based iterations such as jQuery.each() (among others, at about 24:05 in the video). He briefly explains why to avoid them which makes sense, but admittedly I don't quite understand what an alternative would be. Say, in the case I want to iterate through a column of table cells and use the value to manipulate the adjacent cell's value (just a quick example). Can anyone explain and give an example of an alternative to function-based iteration?

    Read the article

  • Java for each vs regular for -- are they equivalent?

    - by polygenelubricants
    Are these two constructs equivalent? char[] arr = new char[5]; for (char x : arr) { // code goes here } Compared to: char[] arr = new char[5]; for (int i = 0; i < arr.length; i++) { char x = arr[i]; // code goes here } That is, if I put exactly the same code in the body of both loops (and they compile), will they behave exactly the same??? Full disclaimer: this was inspired by another question (Java: are these 2 codes the same). My answer there turned out not to be the answer, but I feel that the exact semantics of Java for-each has some nuances that needs pointing out.

    Read the article

  • Blinking an item. (Jquery FadeIn FadeOut ?)

    - by 0plus1
    I have two divs that I want to make blink at the same time until the user hovers the mouse on one of them. var shouldiblink = '1'; function mrBlinko(divid){ while (shouldiblink =='1') { $("#"+divid).fadeIn(100).fadeOut(300); } $(document).ready(function(){ mrBlinko("mydiv1"); mrBlinko("mydiv2"); } The I'll have an hover event that sets shouldiblink to '0'. Problem is that the loops starts as soon as the page is ready and the browser crashes. I'm stuck with this solution and I can't think of an alternative right now. Can you help me? Thank you very much.

    Read the article

  • Php - Looping For Different CSS

    - by bob
    MySQL $selectSize = "SELECT * FROM products"; $querySize = $db->select($selectSize); while ($product = $db->fetcharray($querySize)) { HTML <ul> <li>Product A</li> <li>Product B</li> <li class='right'>Product C</li> <li>Product D</li> <li>Product E</li> <li class='right'>Product F</li> </ul> Question While getting the product, I want the Product C and Product F or any product after 3 loops will have class='right' to the list style. Let me know Thanks

    Read the article

  • showing surrounding page numbers

    - by Tony Vipros
    I've been doing some pagination recently and used the following: if ( $totalPages > $pagesToShow ) { $start = $pageNumber - floor($pagesToShow/2); $end = $pageNumber + floor($pagesToShow/2); while ( $start < 1 ) { $start++; $end++; } while ( $end > $totalPages ) { $start--; $end--; } } else { $start = 1; $end = $totalPages; } to work out where to start and end the list of surrounding pages. So that a paging list can be created like << < 1 2 3 4 5 '. Just wondering if there is a better method as using loops like that seems a little odd.

    Read the article

  • Any way to make this working dual core in C#?

    - by Frantisek
    Hi, I got a piece of code that loops through the array and looks for the similar and same strings in it - marking it whether it's unique or not. loop X array for I ( loop X array for Y ( If X is prefix of Y do. else if x is same length as Y and it's prefix do something. ) Here is the code to finilize everything for I and corresponding (found/not found) matches in Y. ) I'd like to make this for dual-core to multithread it. To my knowledge it is not possible, but it's highly probable that you may have some idea.

    Read the article

  • PHP MYSQL Endless Loop

    - by Neb
    Hi, I have a problem with my php/mysql script. It should only output the while loop once but I am getting unlimited loops and an endless page. $query = mysql_query("SELECT * FROM users WHERE username ='".base64_encode($_SESSION['username'])."' LIMIT 1"); $result = mysql_fetch_array($query); if(empty($result)){ echo "No user... Error"; }else{ while($row = $result){ ?> <a href="index.php?user=<?=$row['id']?>"><?=base64_decode($row['username'])?></a> | <a href="javascript:void(0);" id="logout">Logout</a> <?php } } I have tried a similar script with these same lines and it works perfectly $result = mysql_fetch_array($query); if(empty($result)){ echo "No user... Error"; }else{ while($row = $result){ //Something } }

    Read the article

  • Assigning values to variable WHILE loop

    - by Milaan
    Hi! I have a WHILE loop that loops through a table as long as $i is less than 10. I want this loop to assign the INNERHTML of each cell to a variable. So that I can use it later on to process the information (the loop is because you can choose if it has to take first 3 or first 10 cells). But how do I assign every innerHTML to a different variable? I'm sure there has to be an easy way. But google couldn't get me a good answer. Thanks in advance! Milaan

    Read the article

  • Rails: Accessing previous loop in Populator (rake db:populate)

    - by sscirrus
    I am populating my Rails database using populator, and I have a case where I would like to build a series of records where fields start_date and end_date follow seamlessly from each other (from today back into the past). Here is a sample of what I'm doing: Chain.populate 1 do |ch| ch.date_end = DateTime.now ch.date_start = DateTime.civil(DateTime.now.year-rand(40)-1, rand(12)+1, rand(31)+1) end Chain.populate 0..10 do |chs| chs.date_end = Chain.find(:last).date_start chs.date_start = DateTime.civil(chs.date_end.year-rand(10)-1, rand(12)+1, rand(31)+1) end Problem? undefined method 'date_start' for nil:NilClass. I assume the problem is the first Chain record hasn't been saved, so I added: Chain.save # in between the two loops This didn't work either. How can I make this work? Thank you!

    Read the article

  • VB working with SQL DB - end of row count, keeps looping

    - by Tramd
    I'm adding to a combo box an ID and a name that i'm pulling from a database. My problem is that for some reason my loop doesnt end once it reaches the end of the records in the database table. Here's my code: For intcount = 0 To dtOrders.Rows.Count - 1 cmbSearch.Items.Add(dtOrders.Rows(intcount)("EmployeeID").ToString & " " & dtOrders.Rows(intcount)("EmployeeLastName").ToString & ", " & dtOrders.Rows(intcount)("EmployeeFirstName").ToString) Next Shouldnt the .rows.count - 1 stop it once it reaches the last record? It loops 4 times through.

    Read the article

  • Javascript Canvas Element - Array Of Images

    - by Ben Shelock
    I'm just learning JS, trying to do things without jQuery, and I want to make something similar to this however I want to use an array of images instead of just the one. My image array is formed like this var image_array = new Array() image_array[0] = "image1.jpg" image_array[1] = "image2.jpg" And the canvas element is written like this. (Pretty much entirely taken from the Mozilla site) function draw() { var ctx = document.getElementById('canvas').getContext('2d'); var img = new Image(); img.src = 'sample.png'; img.onload = function(){ for (i=0;i<5;i++){ for (j=0;j<9;j++){ ctx.drawImage(img,j*126,i*126,126,126); } } } } It uses the image "sample.png" in that code but I want to change it to display an image from the array. Displaying a different one each time it loops. Apoligies if I've not explained this well.

    Read the article

  • Python: Importing a variable inside of a infinite loop

    - by Jack
    I have two modules, a host and a scanner. Both loop indefinitely to communicate with the serial ports. I want to import the variable "bestchannel" from scanner into host but by importing it, the while loop inside scanner runs first and loops forever. I want each module to run separately but be able to send each other data in real time. Is this possible? (outside of scanning ram) Example Code: http://pastebin.com/pxUBaima I want minchannel from scanner to be accessible to host.

    Read the article

  • FOR loop performance in Javascript

    - by AndrewMcLagan
    As my research leads me to believe that for loops are the fastest iteration construct in javascript language. I was thinking that also declaring a conditional length value for the for loop would be faster... to make it clearer, which of the following do you think would be faster? Example ONE for(var i = 0; i < myLargeArray.length; i++ ) { console.log(myLargeArray[i]); } Example TWO var count = myLargeArray.length; for(var i = 0; i < count; i++ ) { console.log(myLargeArray[i]); } my logic follows that on each iteration in example one accessing the length of myLargeArray on each iteration is more computationally expensive then accessing a simple integer value as in example two?

    Read the article

  • collect string in loop and printout all the string outside loop

    - by user1508163
    I'm newbie here and there is some question that I want have some lesson from you guys. For example: #include <stdio.h> #include<stdlib.h> #include<ctype.h> void main() { char name[51],selection; do { printf("Enter name: "); fflush(stdin); gets(name); printf("Enter another name?(Y/N)"); scanf("%c",&selection); selection=toupper(selection); }while (selection=='Y'); //I want to printout the entered name here but dunno the coding printf("END\n"); system("pause"); } As I know when the loops perform will overwrite the variable then how I perform a coding that will printout all the name user entered? I have already ask my tutor and he is ask me to use pointer, can anyone guide me in this case?

    Read the article

  • looping and arrays

    - by user1838418
    Hi I'm trying to construct a loop to execute 16 states of the 8 4 2 1 code in (C++) while( condition) { double Bubble[16], Bubble1[16]; Bubble[0] = ( a-2 - (b-2) ) + ( c-2 - (d-2)); // represents 0000 Bubble[1] = ( a-2 - (b-2) ) + ( c-2 - (d+2)); // represents 0001 Bubble[2] = ( a-2 - (b-2) ) + ( c+2 - (d-2)); // represents 0010 Bubble[3] = ( a-2 - (b-2) ) + ( c+2 - (d+2)); //represents 0011 ....... Bubble[15] =(a+2 - (b+2) ) + ( c+2 - (d+2)); //represents 1111 } Is there an easy way of coding using for loops? instead of writing bubble[] every time? 0 stands for -2 and 1 stands for +2. So I have 4 variables and each one need to be incremented and/or decremented. Can this be done using for loop? Appreciate your help

    Read the article

  • Why use a "do while" loop?

    - by Stanni
    Hi, I've never understood why using a do while loops is necessary. I understand what they do, Which is to execute the code that the while loop contains without checking if the condition is true first. But isn't the below code: do{ document.write("ok"); } while(x == "10"){ document.write("ok"); } The exact same as: document.write("ok"); while(x == "10"){ document.write("ok"); } Maybe I'm being very stupid and missing something obvious out but I don't see the benefit of using do while over my above example.

    Read the article

  • Importing data from many excel workbooks and sheets into a single workbook/table

    - by Max Rusalen
    Hi, I have 54 excel files with three sheets each, each sheet has a different amount of data entries but they are set out in a identical format, and I need to import the data from those sheets into a single workbook using VBA. Is there any way I can program it so I can build the loops to import the data, but without having to write in each workbook name for each loop/sheet? I think I can use the call function, but I don't know how to make the loop codes independent of the workbook name they apply to. Thank you so much in advance, Millie

    Read the article

  • Add incremental numbers at the end of a string in a loop in Javascript.

    - by Kyle Sevenoaks
    This Javascript is part of a Foreach loop. var stickytooltip={ tooltipoffsets: [20, -30], //additional x and y offset from mouse cursor for tooltips fadeinspeed: 200, //duration of fade effect in milliseconds rightclickstick: false, //sticky tooltip when user right clicks over the triggering element (apart from pressing "s" key) ? stickybordercolors: ["#0a5692", "#0a5692"], //border color of tooltip depending on sticky state stickynotice: ["Press \"s\"", "or right click", "to sticky box"], //customize tooltip status message stickynotice2: "Click outside this box to hide it", //customize tooltip status message //***** NO NEED TO EDIT BEYOND HERE isdocked: false, positiontooltip:function($, $tooltip, e){ var x=e.pageX+this.tooltipoffsets[0], y=e.pageY+this.tooltipoffsets[1] var tipw=$tooltip.outerWidth(), tiph=$tooltip.outerHeight(), x=(x+tipw>$(document).scrollLeft()+$(window).width())? x-tipw-(stickytooltip.tooltipoffsets[0]*2) : x y=(y+tiph>$(document).scrollTop()+$(window).height())? $(document).scrollTop()+$(window).height()-tiph-10 : y $tooltip.css({left:x, top:y}) }, showbox:function($, $tooltip, e){ $tooltip.fadeIn(this.fadeinspeed) this.positiontooltip($, $tooltip, e) }, hidebox:function($, $tooltip){ if (!this.isdocked){ $tooltip.stop(false, true).hide() $tooltip.css({borderColor:'black'}).find('.stickystatus:eq(0)').css({background:this.stickybordercolors[0]}).html(this.stickynotice) } }, docktooltip:function($, $tooltip, e){ this.isdocked=true $tooltip.css({borderColor:'darkred'}).find('.stickystatus:eq(0)').css({background:this.stickybordercolors[1]}).html(this.stickynotice) }, init:function(targetselector, tipid){ jQuery(document).ready(function($){ var $targets=$(targetselector) var $tooltip=$('#'+tipid).appendTo(document.body) if ($targets.length==0) return var $alltips=$tooltip.find('div.atip') if (!stickytooltip.rightclickstick) stickytooltip.stickynotice[1]='' stickytooltip.stickynotice=stickytooltip.stickynotice.join(' ') stickytooltip.hidebox($, $tooltip) $targets.bind('mouseenter', function(e){ $alltips.hide().filter('#'+$(this).attr('data-tooltip')).show() stickytooltip.showbox($, $tooltip, e) }) $targets.bind('mouseleave', function(e){ stickytooltip.hidebox($, $tooltip) }) $targets.bind('mousemove', function(e){ if (!stickytooltip.isdocked){ stickytooltip.positiontooltip($, $tooltip, e) } }) $tooltip.bind("mouseenter", function(){ stickytooltip.hidebox($, $tooltip) }) $tooltip.bind("click", function(e){ e.stopPropagation() }) $(this).bind("click", function(e){ if (e.button==0){ stickytooltip.isdocked=false stickytooltip.hidebox($, $tooltip) } }) $(this).bind("contextmenu", function(e){ if (stickytooltip.rightclickstick && $(e.target).parents().andSelf().filter(targetselector).length==1){ //if oncontextmenu over a target element stickytooltip.docktooltip($, $tooltip, e) return false } }) $(this).bind('keypress', function(e){ var keyunicode=e.charCode || e.keyCode if (keyunicode==115){ //if "s" key was pressed stickytooltip.docktooltip($, $tooltip, e) } }) }) //end dom ready } } //stickytooltip.init("targetElementSelector", "tooltipcontainer") stickytooltip.init("*[data-tooltip]", "mystickytooltip") I need to just add some code to the end of "mystickytooltip" to add 1, 2, 3, 4 each time it loops. My JS-foo is nonexistant, please help :)

    Read the article

  • How to use a loop to download HTML with paging?

    - by Nai
    I want to loop through this URL and download the HTML. https://www.googleapis.com/customsearch/v1?key=AIzaSyAAoPQprb6aAV-AfuVjoCdErKTiJHn-4uI&cx=017576662512468239146:omuauf_lfve&q=" + searchTermFormat + "&num=10" +"&start=" + i start and num controls the paging of the URL. So if &start=2, and &num=10, it will scrape 10 results from page 2. Given that Google has a max limit of num = 10, how can I write a loop that loops through the HTML and scrape the results for the first 10 pages? This is what I have so far which just scrapes the first page. //input search term Console.WriteLine("What is your search query?:"); string searchTerm = Console.ReadLine(); //concantenate the strings using + symbol to make it URL friendly for google string searchTermFormat = searchTerm.Replace(" ", "+"); //create a new instance of Webclient and use DownloadString method from the Webclient class to extract download html WebClient client = new WebClient(); int i = 1; string Json = client.DownloadString("https://www.googleapis.com/customsearch/v1?key=AIzaSyAAoPQprb6aAV-AfuVjoCdErKTiJHn-4uI&cx=017576662512468239146:omuauf_lfve&q=" + searchTermFormat + "&num=10" + "&start=" + i); //create a new instance of JavaScriptSerializer and deserialise the desired content JavaScriptSerializer js = new JavaScriptSerializer(); GoogleSearchResults results = js.Deserialize<GoogleSearchResults>(Json); //output results to console Console.WriteLine(js.Serialize(results)); Console.ReadLine();

    Read the article

  • Need Associated ID Added to a While Loop (php)

    - by user319361
    Been trying to get my head around while loops for the last few days but the code seems very inefficient for what Im trying to achieve. I'm assuming I'm overcomplicating this though nothing I've tried seems to work. Each topic in my forum can have related topic IDs stored in a seperate table. A post ID is also stored in this table, as that specific post references why they are considered related. DB Table contains only: topic_id, related_id, post_id // Get related IDs and post IDs for current topic being viewed $result = $db->query('SELECT related_id, post_id FROM related_topics WHERE topic_id='.$id.''); // If related topics found, put both of the IDs into arrays if ($db->num_rows($result)) { while($cur_related = mysql_fetch_array($result)){ $reltopicarray[] = $cur_related['related_id']; $relpost[] = $cur_related['post_id']; } // If the first array isnt empty, get some additional info about each related ID from another table if(!empty($reltopicarray)) { $pieces = $reltopicarray; $glued = "\"".implode('", "', $pieces)."\""; $fetchtopics = $db->query('SELECT id, subject, author, image, etc FROM topics WHERE id IN('.$glued.')'); } // Print each related topic while($related = mysql_fetch_array($fetchtopics)){ ?> <a href="view.php?id=<?php echo $related['id']; ?>"><?php echo $related['subject']; ?></a> by <?php echo $related['author']; ?> // Id like to show the Post ID below (from the array in the first while loop) // The below link doesnt work as Im outside the while loop by this point. <br /><a href="view.php?post_id=<?php echo $cur_related['post_id']; ?>">View Relationship</a> <?php } ?> The above currently works, however I'm trying to also display the post_id link below each related topic link, as shown above. Would be greatful if someone can lend a hand. Thanks :)

    Read the article

  • Skipping the BufferedReader readLine() method in java

    - by DDP
    Is there a easy way to skip the readLine() method in java if it takes longer than, say, 2 seconds? Here's the context in which I'm asking this question: public void run() { boolean looping = true; while(looping) { for(int x = 0; x<clientList.size(); x++) { try { Comm s = clientList.get(x); String str = s.recieve(); // code that does something based on the string in the line above } // other stuff like catch methods } } } Comm is a class I wrote, and the receive method, which contains a BufferedReader called "in", is this: public String recieve() { try { if(active) return in.readLine(); } catch(Exception e) { System.out.println("Comm Error 2: "+e); } return ""; } I've noticed that the program stops and waits for the input stream to have something to read before continuing. Which is bad, because I need the program to keep looping (as it loops, it goes to all the other clients and asks for input). Is there a way to skip the readLine() process if there's nothing to read? I'm also pretty sure that I'm not explaining this well, so please ask me questions if I'm being confusing.

    Read the article

  • Coding the R-ight way - avoiding the for loop

    - by mropa
    I am going through one of my .R files and by cleaning it up a little bit I am trying to get more familiar with writing the code the r-ight way. As a beginner, one of my favorite starting points is to get rid of the for() loops and try to transform the expression into a functional programming form. So here is the scenario: I am assembling a bunch of data.frames into a list for later usage. dataList <- list (dataA, dataB, dataC, dataD, dataE ) Now I like to take a look at each data.frame's column names and substitute certain character strings. Eg I like to substitute each "foo" and "bar" with "baz". At the moment I am getting the job done with a for() loop which looks a bit awkward. colnames(dataList[[1]]) [1] "foo" "code" "lp15" "bar" "lh15" colnames(dataList[[2]]) [1] "a" "code" "lp50" "ls50" "foo" matchVec <- c("foo", "bar") for (i in seq(dataList)) { for (j in seq(matchVec)) { colnames (dataList[[i]])[grep(pattern=matchVec[j], x=colnames (dataList[[i]]))] <- c("baz") } } Since I am working here with a list I thought about the lapply function. My attempts handling the job with the lapply function all seem to look alright but only at first sight. If I write f <- function(i, xList) { gsub(pattern=c("foo"), replacement=c("baz"), x=colnames(xList[[i]])) } lapply(seq(dataList), f, xList=dataList) the last line prints out almost what I am looking for. However, if i take another look at the actual names of the data.frames in dataList: lapply (dataList, colnames) I see that no changes have been made to the initial character strings. So how can I rewrite the for() loop and transform it into a functional programming form? And how do I substitute both strings, "foo" and "bar", in an efficient way? Since the gsub() function takes as its pattern argument only a character vector of length one.

    Read the article

  • ForEach loop: Output something different on every second result

    - by Wade D Ouellet
    I have two for each loops and I am trying to output something different for each second result: foreach ($wppost as $wp) { $wp_title = $wp->post_title; $wp_date = strtotime($wp->post_date); $wp_slug = $wp->post_name; $wp_id = $wp->ID; // Start Permalink Template $wp_showurl = $wp_url; $wp_showurl = str_replace("%year%", date('Y', $wp_date), $wp_showurl); $wp_showurl = str_replace("%monthnum%", date('m', $wp_date), $wp_showurl); $wp_showurl = str_replace("%day%", date('d', $wp_date), $wp_showurl); $wp_showurl = str_replace("%hour%", date('H', $wp_date), $wp_showurl); $wp_showurl = str_replace("%minute%", date('i', $wp_date), $wp_showurl); $wp_showurl = str_replace("%second%", date('s', $wp_date), $wp_showurl); $wp_showurl = str_replace("%postname%", $wp_slug, $wp_showurl); $wp_showurl = str_replace("%post_id%", $wp_id, $wp_showurl); // Stop Permalink Template $wp_posturl = $blog_address . $wp_showurl; echo '<li><a href="'.$wp_posturl.'" title="'.$wp_title.'">'.$wp_title.'</a></li>'; } For this one I want it to echo li class="even" instead of just li for each second result. I think this will have to be changed to a for loop to accomplished this but I am not sure how that is done without breaking it. Exact same for this one: if(is_array($commenters)) { foreach ($commenters as $k) { ?><li><?php if($ns_options["make_links"] == 1) { $url = ns_get_user_url($k->poster_id); if(trim($url) != '') { echo "<a href='" . $url . "'>"; } } if($ns_options["make_links"] == 2) { $url = ns_get_user_profile($k->poster_id); echo "<a href='" . $url . "'>"; } $name = $bbdb->get_var(" SELECT user_login FROM $bbdb->users WHERE ID = $k->poster_id"); echo ns_substr_ellipse($name, $ns_options["name_limit"]); if(trim($url) != '' && $ns_options["make_links"] == 1) { echo "</a>"; } if($ns_options["make_links"] == 2) { echo "</a>"; } if ($ns_options["show_posts"] == 1) { echo " (" . $k->num_posts . ")\n"; } echo $ns_options["end_html"] . "\n"; unset($url); } } else { ?></li><?php } Thanks, Wade

    Read the article

  • Grouping Months of a particular Time span together using DateTime.

    - by Calibre2010
    public static string TimeLine2(this HtmlHelper helper, string myString2) { StringBuilder myString3 = new StringBuilder(); DateTime start = new DateTime(2010, 1, 1); DateTime end = new DateTime(2011, 12, 12); myString3.Append("<table>"); myString3.Append("<tr>"); for (DateTime date = start; date <= end; date = date.AddDays(1)) { DayOfWeek dw = date.DayOfWeek; var g = date.Month; var sun = " "; switch (dw) { case DayOfWeek.Sunday: sun = "S"; break; case DayOfWeek.Monday: sun = "M"; break; case DayOfWeek.Tuesday: sun = "T"; break; case DayOfWeek.Wednesday: sun = "W"; break; case DayOfWeek.Thursday: sun = "T"; break; case DayOfWeek.Friday: sun = "F"; break; case DayOfWeek.Saturday: sun = "S"; break; } myString3.Append("<td>" + sun + " " + g + "</td>"); } myString3.Append("</tr>"); myString3.Append("<tr>"); for (DateTime date = start; date <= end; date = date.AddDays(1)) { var f = date.Day; myString3.Append("<td>" + f + "</td>"); } myString3.Append("</tr>"); myString3.Append("</table>"); return myString3.ToString(); } Basically, what I have here is a few loops showing all the days of the week and also all the days in a month. This is all placed inside of a table, so you get MTWTFSSMT W T F S S M M TWTFSSM 12345678910 11 12 13 14 + + to 31 1234567 I'm trying to code a way in which I can split all of these days of the week and days in months so that my code returns each month with all its days in the month and all its days of the week, not just all my months between my timeSpan but splits them so MAY MTWTFSSMTWTFSSMTWTFSSMTWTFSSMTWTF 12345678 JUNE MTWTFSSMTWTFSSMTWTFSSMTWTFSSMTWTF 123456789

    Read the article

  • Can my loop be optimized any more? (C++)

    - by Sagekilla
    Below is one of my inner loops that's run several thousand times, with input sizes of 20 - 1000 or more. Is there anything I can do to help squeeze any more performance out of this? I'm not looking to move this code to something like using tree codes (Barnes-Hut), but towards optimizing the actual calculations happening inside, since the same calculations occur in the Barnes-Hut algorithm. Any help is appreciated! typedef double real; struct Particle { Vector pos, vel, acc, jerk; Vector oldPos, oldVel, oldAcc, oldJerk; real mass; }; class Vector { private: real vec[3]; public: // Operators defined here }; real Gravity::interact(Particle *p, size_t numParticles) { PROFILE_FUNC(); real tau_q = 1e300; for (size_t i = 0; i < numParticles; i++) { p[i].jerk = 0; p[i].acc = 0; } for (size_t i = 0; i < numParticles; i++) { for (size_t j = i+1; j < numParticles; j++) { Vector r = p[j].pos - p[i].pos; Vector v = p[j].vel - p[i].vel; real r2 = lengthsq(r); real v2 = lengthsq(v); // Calculate inverse of |r|^3 real r3i = Constants::G * pow(r2, -1.5); // da = r / |r|^3 // dj = (v / |r|^3 - 3 * (r . v) * r / |r|^5 Vector da = r * r3i; Vector dj = (v - r * (3 * dot(r, v) / r2)) * r3i; // Calculate new acceleration and jerk p[i].acc += da * p[j].mass; p[i].jerk += dj * p[j].mass; p[j].acc -= da * p[i].mass; p[j].jerk -= dj * p[i].mass; // Collision estimation // Metric 1) tau = |r|^2 / |a(j) - a(i)| // Metric 2) tau = |r|^4 / |v|^4 real mij = p[i].mass + p[j].mass; real tau_est_q1 = r2 / (lengthsq(da) * mij * mij); real tau_est_q2 = (r2*r2) / (v2*v2); if (tau_est_q1 < tau_q) tau_q = tau_est_q1; if (tau_est_q2 < tau_q) tau_q = tau_est_q2; } } return sqrt(sqrt(tau_q)); }

    Read the article

< Previous Page | 5 6 7 8 9 10 11 12 13 14 15 16  | Next Page >