49 lines
1.7 KiB
JavaScript
49 lines
1.7 KiB
JavaScript
|
var test = require('tape');
|
||
|
|
var ss = require('../');
|
||
|
|
|
||
|
|
test('sample skewness', function(t) {
|
||
|
|
|
||
|
|
test('the skewness of an empty sample is null', function(t) {
|
||
|
|
var data = [];
|
||
|
|
t.equal(ss.sample_skewness(data), null);
|
||
|
|
t.end();
|
||
|
|
});
|
||
|
|
|
||
|
|
test('the skewness of an sample with one number is null', function(t) {
|
||
|
|
var data = [1];
|
||
|
|
t.equal(ss.sample_skewness(data), null);
|
||
|
|
t.end();
|
||
|
|
});
|
||
|
|
|
||
|
|
test('the skewness of an sample with two numbers is null', function(t) {
|
||
|
|
var data = [1, 2];
|
||
|
|
t.equal(ss.sample_skewness(data), null);
|
||
|
|
t.end();
|
||
|
|
});
|
||
|
|
|
||
|
|
test('can calculate the skewness of SAS example 1', function(t) {
|
||
|
|
// Data and answer taken from SKEWNESS function documentation at
|
||
|
|
// http://support.sas.com/documentation/c../lrdict/64316/HTML/default/viewer.htm#a000245947.htm
|
||
|
|
var data = [0, 1, 1];
|
||
|
|
t.equal(+ss.sample_skewness(data).toPrecision(10), -1.732050808);
|
||
|
|
t.end();
|
||
|
|
});
|
||
|
|
|
||
|
|
test('can calculate the skewness of SAS example 2', function(t) {
|
||
|
|
// Data and answer taken from SKEWNESS function documentation at
|
||
|
|
// http://support.sas.com/documentation/c../lrdict/64316/HTML/default/viewer.htm#a000245947.htm
|
||
|
|
var data = [2, 4, 6, 3, 1];
|
||
|
|
t.equal(+ss.sample_skewness(data).toPrecision(10), 0.5901286564);
|
||
|
|
t.end();
|
||
|
|
});
|
||
|
|
|
||
|
|
test('can calculate the skewness of SAS example 3', function(t) {
|
||
|
|
// Data and answer taken from SKEWNESS function documentation at
|
||
|
|
// http://support.sas.com/documentation/c../lrdict/64316/HTML/default/viewer.htm#a000245947.htm
|
||
|
|
var data = [2, 0, 0];
|
||
|
|
t.equal(+ss.sample_skewness(data).toPrecision(10), 1.732050808);
|
||
|
|
t.end();
|
||
|
|
});
|
||
|
|
t.end();
|
||
|
|
});
|