d3/test/layout/histogram-test.js

96 строки
2.7 KiB
JavaScript

require("../env");
var vows = require("vows"),
assert = require("assert");
var suite = vows.describe("d3.layout.histogram");
suite.addBatch({
"histogram": {
topic: function() {
return d3.layout.histogram;
},
"defaults to frequencies": function(histogram) {
var h = histogram();
assert.deepEqual(h([0,0,0,1,2,2]).map(elements), [[0, 0, 0], [], [1], [2, 2]]);
},
"each bin contains the matching source elements": function(histogram) {
var h = histogram();
assert.deepEqual(h([0,0,0,1,2,2]).map(elements), [[0, 0, 0], [], [1], [2, 2]]);
},
"each bin also has defined x, y and dx properties": function(histogram) {
var h = histogram();
assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [
{x: 0, y: 3, dx: 0.5},
{x: 0.5, y: 0, dx: 0.5},
{x: 1, y: 1, dx: 0.5},
{x: 1.5, y: 2, dx: 0.5}
]);
},
"can output frequencies": function(histogram) {
var h = histogram().frequency(true);
assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [
{x: 0, y: 3, dx: 0.5},
{x: 0.5, y: 0, dx: 0.5},
{x: 1, y: 1, dx: 0.5},
{x: 1.5, y: 2, dx: 0.5}
]);
},
"can output probabilities": function(histogram) {
var h = histogram().frequency(false);
assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [
{x: 0, y: 3/6, dx: 0.5},
{x: 0.5, y: 0, dx: 0.5},
{x: 1, y: 1/6, dx: 0.5},
{x: 1.5, y: 2/6, dx: 0.5}
]);
},
"can specify number of bins": function(histogram) {
var h = histogram().bins(2);
assert.deepEqual(h([0,0,0,1,2,2]).map(elements), [
[0, 0, 0],
[1, 2, 2]
]);
assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [
{x: 0, y: 3, dx: 1},
{x: 1, y: 3, dx: 1}
]);
},
"can specify bin thresholds": function(histogram) {
var h = histogram().bins([0,1,2,3]);
assert.deepEqual(h([0,0,0,1,2,2]).map(elements), [
[0, 0, 0],
[1],
[2, 2]
]);
assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [
{x: 0, y: 3, dx: 1},
{x: 1, y: 1, dx: 1},
{x: 2, y: 2, dx: 1}
]);
},
"returns the empty array with fewer than two bins": function(histogram) {
var h = histogram().bins([1]);
assert.deepEqual(h([0]), []);
var h = histogram().bins([]);
assert.deepEqual(h([0]), []);
}
}
});
function elements(bin) {
var array = [], i = -1, n = bin.length;
while (++i < n) array.push(bin[i]);
return array;
}
function metadata(bin) {
var metadata = {};
if ("x" in bin) metadata.x = bin.x;
if ("y" in bin) metadata.y = bin.y;
if ("dx" in bin) metadata.dx = bin.dx;
return metadata;
}
suite.export(module);