38 lines
1.1 KiB
JavaScript
38 lines
1.1 KiB
JavaScript
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import { Math } from 'angular2/src/facade/math';
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import { ListWrapper } from 'angular2/src/facade/collection';
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export class Statistic {
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static calculateCoefficientOfVariation(sample, mean) {
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return Statistic.calculateStandardDeviation(sample, mean) / mean * 100;
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}
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static calculateMean(sample) {
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var total = 0;
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ListWrapper.forEach(sample, (x) => { total += x } );
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return total / sample.length;
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}
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static calculateStandardDeviation(sample, mean) {
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var deviation = 0;
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ListWrapper.forEach(sample, (x) => {
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deviation += Math.pow(x - mean, 2);
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});
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deviation = deviation / (sample.length);
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deviation = Math.sqrt(deviation);
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return deviation;
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}
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static calculateRegressionSlope(xValues, xMean, yValues, yMean) {
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// See http://en.wikipedia.org/wiki/Simple_linear_regression
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var dividendSum = 0;
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var divisorSum = 0;
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for (var i=0; i<xValues.length; i++) {
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dividendSum += (xValues[i] - xMean) * (yValues[i] - yMean);
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divisorSum += Math.pow(xValues[i] - xMean, 2);
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}
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return dividendSum / divisorSum;
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}
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}
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