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mkuklis/LICENSE.txt

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annotated.js
function(
a, // old rating
b, // opponent rating
c, // result 0 - lost 0.5 - draw 1 - win
e, // expected probability
k // k-factor
){
e = 1 / (1 + Math.pow(10, ((b - a) / 400))); // calculate probability
// find k-factor
if (b < 2100) k = 32;
else if (b >= 2100 && b <= 2400) k = 24;
else if (b > 2400) k = 16;
return b + k * (c - e); // return new rating
}
Raw
index.js
function(a,b,c,e,k){e=1/(1+Math.pow(10,((b-a)/400)));if(b<2100)k=32;else if(b>=2100&&b<=2400)k=24;else if(b>2400)k=16;return b+k*(c-e)}
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LICENSE.txt
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.
Raw
package.json
{
"name": "elo",
"description": "Elo rating calculation",
"keywords": [
"game",
"elo",
"rating",
"calculation"
]
}
Raw
test.html
<!DOCTYPE html>
<title>Foo</title>
<div>Expected value: <b>1316</b></div>
<div>Actual value: <b id="ret"></b></div>
<script>
var elo = function(a,b,c,e,k){e=1/(1+Math.pow(10,((b-a)/400)));if(b<2100)k=32;else if(b>=2100&&b<=2400)k=24;else if(b>2400)k=16;return b+k*(c-e)}
document.getElementById( "ret" ).innerHTML = elo(1300, 1300, 1);
</script>
@atk
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atk commented Jul 8, 2013

Allow me to be your caddy for this code golf:

function(a,b,c){return b+(b<2100?32:b<2401?24:16)*(c-(1/(1+Math.pow(10,((b-a)/400)))))}

@mkuklis
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mkuklis commented Jul 19, 2013

@atk fantastic! Thank you!

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