var vows = require(“vows”),
load = require("../load"), assert = require("../assert");
var suite = vows.describe(“d3.quantile”);
suite.addBatch({
"quantile": { topic: load("arrays/quantile").expression("d3.quantile"), "requires sorted numeric input": function(quantile) { assert.equal(quantile([1, 2, 3, 4], 0), 1); assert.equal(quantile([1, 2, 3, 4], 1), 4); assert.equal(quantile([4, 3, 2, 1], 0), 4); assert.equal(quantile([4, 3, 2, 1], 1), 1); }, "uses the R-7 algorithm": function(quantile) { var data = [3, 6, 7, 8, 8, 10, 13, 15, 16, 20]; assert.equal(quantile(data, 0), 3); assert.equal(quantile(data, .25), 7.25); assert.equal(quantile(data, .5), 9); assert.equal(quantile(data, .75), 14.5); assert.equal(quantile(data, 1), 20); var data = [3, 6, 7, 8, 8, 9, 10, 13, 15, 16, 20]; assert.equal(quantile(data, 0), 3); assert.equal(quantile(data, .25), 7.5); assert.equal(quantile(data, .5), 9); assert.equal(quantile(data, .75), 14); assert.equal(quantile(data, 1), 20); }, "coerces values to numbers": function(quantile) { var strings = ["1", "2", "3", "4"]; assert.strictEqual(quantile(strings, 1/3), 2); assert.strictEqual(quantile(strings, 1/2), 2.5); assert.strictEqual(quantile(strings, 2/3), 3); var dates = [new Date(2011, 0, 1), new Date(2012, 0, 1)]; assert.strictEqual(quantile(dates, 0), +new Date(2011, 0, 1)); assert.strictEqual(quantile(dates, 1/2), +new Date(2011, 6, 2, 13)); assert.strictEqual(quantile(dates, 1), +new Date(2012, 0, 1)); }, "returns an exact value for integer p-values": function(quantile) { var data = [1, 2, 3, 4]; assert.equal(quantile(data, 1/3), 2); assert.equal(quantile(data, 2/3), 3); }, "returns the first value for p = 0": function(quantile) { var data = [1, 2, 3, 4]; assert.equal(quantile(data, 0), 1); }, "returns the last value for p = 1": function(quantile) { var data = [1, 2, 3, 4]; assert.equal(quantile(data, 1), 4); } }
});
suite.export(module);