39 lines
1.0 KiB
JavaScript
39 lines
1.0 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('sample variance', function(t) {
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test('can get the sample variance of a six-sided die', function(t) {
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t.equal(rnd(ss.sample_variance([1, 2, 3, 4, 5, 6])), 3.5);
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t.end();
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});
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// confirmed in R
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//
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// > var(1:10)
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// [1] 9.166667
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test('can get the sample variance of numbers 1-10', function(t) {
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t.equal(rnd(ss.sample_variance([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])), 9.167);
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t.end();
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});
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test('the sample variance of two numbers that are the same is 0', function(t) {
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t.equal(rnd(ss.sample_variance([1, 1])), 0);
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t.end();
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});
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test('the sample variance of one number is null', function(t) {
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t.equal(ss.sample_variance([1]), null);
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t.end();
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});
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test('the sample variance of no numbers is null', function(t) {
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t.equal(ss.sample_variance([]), null);
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t.end();
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});
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t.end();
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});
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