-
-
Save arextar/1246238 to your computer and use it in GitHub Desktop.
Summation function
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| function( | |
| a, //Lower bound | |
| b, //Upper bound | |
| c, //[Step function] | |
| d, //Multiply | |
| e,f //Placeholders | |
| ){ | |
| c===true&&(d=c,c=0); //If c is true, use c as the 'multiply' param | |
| if(a==1&&!c&&!d) return (b*b+b)/2 //If it's a standard summation of 1..n, optimize | |
| for( | |
| e=!!d //initiate counter as d (will coerce to 0 if adding, 1 if multiplying) | |
| ;a<=b; //While lower bound is less than the upper bound... | |
| f=c?c(b):b, //If a step function is passed, use it | |
| d?e*=f:e+=f, //Perform the necessary operation | |
| b-- //Decrement the upper bound | |
| ); | |
| return e; //Return the result of the summation | |
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| function(a,b,c,d,e,f){c===!0&&(d=c,c=0);if(a==1&&!c&&!d)return(b*b+b)/2;for(e=!!d;a<=b;f=c?c(b):b,d?e*=f:e+=f,b--);return e} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE | |
| Version 2, December 2004 | |
| Copyright (C) 2011 YOUR_NAME_HERE <YOUR_URL_HERE> | |
| Everyone is permitted to copy and distribute verbatim or modified | |
| copies of this license document, and changing it is allowed as long | |
| as the name is changed. | |
| DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE | |
| TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION | |
| 0. You just DO WHAT THE FUCK YOU WANT TO. |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| { | |
| "name": "summation", | |
| "description": "A function to execute a summation in JavaScript. Support for a step function and multiplication", | |
| "keywords": [ | |
| "math" | |
| ] | |
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!DOCTYPE html> | |
| <title>Summation</title> | |
| <div>Expected value: <b>[5050, 5049, -15, 120]</b></div> | |
| <div>Actual value: <b id="ret"></b></div> | |
| <script> | |
| var summate = function(a,b,c,d,e,f){c===!0&&(d=c,c=0);if(a==1&&!c&&!d)return(b*b+b)/2;for(e=!!d;a<=b;f=c?c(b):b,d?e*=f:e+=f,b--);return e} | |
| document.getElementById( "ret" ).innerHTML = "["+[ | |
| summate(1,100), | |
| summate(2,100), | |
| summate(1,5,function(n){ | |
| return -n; | |
| }), | |
| summate(1,5,true)].join(", ")+"]" | |
| </script> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment