Method Function.time

Get the execution time of a function

• Syntax Object Function.time(Number n , Mixed obj , [ Mixed a2 ... an ])
  
  This method will time a function n times.
  
  If obj is null then the function is timed as a standard function. If obj is a valid object reference then the function is timed as a method of obj.
  
  Any extra arguments a2...an are passed to the function/method being timed.
  
  A default toString method is assigned to the return object allowing for easy interpretation of the result.
• Parameters

  Number n

  The number of times to run the test.

  Mixed obj

  Pass null to time the function as a normal function. If you pass an object reference the function is executed as a method of obj.

  Mixed a2 ... an (Optional)

  The arguments you wish to pass to the function/method being tested

• Return value A custom object obj with following properties
  
obj.f - A reference to the function being timed
obj.n - The number of times the function was executed
obj.mean - The average time for a function execution
obj.s - The variation
obj.sd - The standard deviation

  All times reported are in milliseconds.
• Examples

  To test the execution time of the function f 25 times

  f.time(25);

  To test the execution time of the function fnc(a,b) {a * b;} 25 times passing the arguments 10 and 34 to fnc

  fnc.time(25,null,10,34);

  To test the execution time of the function fnc(a,b) {a * b;} 25 times as a method of object o, passing the arguments 10 and 34 to fnc

  fnc.time(25,o,10,34);

• Download
  Download this function including dependencies
  Source

  Unless otherwise noted all code in the JSLab Standard Library is licensed as GPLv3. See http://www.gnu.org/licenses/gpl.html for the entire license.

  This function has dependencies and will not work stand-alone. Use the download button above instead of copy/paste.

  // ************************************************************************** // Copyright 2007 - 2009 Tavs Dokkedahl // Contact: http://www.jslab.dk/contact.php // // This file is part of the JSLab Standard Library (JSL) Program. // // JSL is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 3 of the License, or // any later version. // // JSL is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program. If not, see <http://www.gnu.org/licenses/>. // *************************************************************************** // Time a function n times and return a custom object with statistics for the trials Function.prototype.time = function(n,obj) { if (n < 1) return; var o = {f:this, a:[], n:n, mean:0, s:0, sd: 0}; for(var i=2; i<arguments.length; i++) o.a.push(arguments[i]); var t1,t2; var t = ts = 0; for(var i=0; i<n; i++) { t1 = new Date(); this.apply(obj,o.a); t2 = (new Date()) - t1; t += t2; ts += t2 * t2; } o.mean = t / n; o.s = n > 1 ? (ts - t * o.mean) / ( n - 1) : 0; o.sd = Math.sqrt(o.s); o.toString = function() { return 'Running ' + this.f.getName() + ' ' + this.n + ' times:\n\nMean:\t'+ (this.mean).toFixed(8) + '\nVariance:\t' + (this.s).toFixed(8) + '\nSD:\t' + (this.sd).toFixed(8); }; return o; };