40 lines
1.1 KiB
JavaScript
40 lines
1.1 KiB
JavaScript
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var test = require('tape');
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var ss = require('../');
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function rnd(x) {
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return Math.round(x * 1000) / 1000;
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}
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test('standard_deviation', function(t) {
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test('can get the standard deviation of an example on wikipedia', function(t) {
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t.equal(rnd(ss.standard_deviation([2, 4, 4, 4, 5, 5, 7, 9])), 2);
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t.end();
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});
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// confirmed with numpy
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// In [4]: numpy.std([1,2,3])
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// Out[4]: 0.81649658092772603
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test('can get the standard deviation of 1-3', function(t) {
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t.equal(rnd(ss.standard_deviation([1, 2, 3])), 0.816);
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t.end();
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});
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test('zero-length array corner case', function(t) {
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t.equal(rnd(ss.standard_deviation([])), 0);
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t.end();
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});
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// In [6]: numpy.std([0,1,2,3,4,5,6,7,8,9,10])
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// Out[6]: 3.1622776601683795
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test('can get the standard deviation of 1-10', function(t) {
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t.equal(rnd(ss.standard_deviation([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10])), 3.162);
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t.end();
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});
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test('the standard deviation of one number is zero', function(t) {
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t.equal(rnd(ss.standard_deviation([1])), 0);
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t.end();
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});
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t.end();
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});
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