filer/perf/simple-statistics/test/variance.test.js

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2014-12-16 23:53:29 +00:00
var test = require('tape');
var ss = require('../');
function rnd(x) {
return Math.round(x * 1000) / 1000;
}
test('variance', function(t) {
test('can get the variance of a six-sided die', function(t) {
t.equal(rnd(ss.variance([1, 2, 3, 4, 5, 6])), 2.917);
t.end();
});
test('the variance of one number is zero', function(t) {
t.equal(rnd(ss.variance([1])), 0);
t.end();
});
test('the variance of no numbers is null', function(t) {
t.equal(ss.variance([]), null);
t.end();
});
t.end();
});