41 lines
1.1 KiB
JavaScript
41 lines
1.1 KiB
JavaScript
function distcheck(random_func, times, opts) {
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if (opts === undefined) opts = {}
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opts['delta'] = opts['delta'] || 2;
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var count = {}, vals = [];
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for (var i = 0; i < times; i++) {
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var val = random_func();
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if (! has_property(count, val)) {
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count[val] = 1;
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vals.push(val);
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}
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else
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count[val] ++;
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}
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vals.sort(function(a,b) {return a-b});
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var target = times / vals.length;
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var tolerance = target * opts['delta'] / 100;
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for (var i = 0; i < vals.length; i++) {
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var val = vals[i];
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if (Math.abs(count[val] - target) > tolerance)
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throw "distribution potentially skewed for " + val +
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": expected result around " + target + ", got " +count[val];
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else
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print(val + "\t" + count[val]);
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}
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}
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function has_property(obj, propname) {
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return typeof(obj[propname]) == "undefined" ? false : true;
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}
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try {
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distcheck(function() {return Math.floor(10 * Math.random())}, 100000);
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print();
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distcheck(function() {return (Math.random() > 0.95 ? 1 : 0)}, 100000);
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} catch (e) {
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print(e);
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}
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