Add test for scale.quantile.

test/scale/quantile-test.js

@@ -0,0 +1,64 @@
+require("../env");
+require("../../d3");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.scale.quantile");
+
+suite.addBatch({
+  "quantile": {
+    topic: function() {
+      return d3.scale.quantile;
+    },
+    "has the empty domain by default": function(quantile) {
+      assert.isEmpty(quantile().domain());
+    },
+    "has the empty range by default": function(quantile) {
+      assert.isEmpty(quantile().range());
+    },
+    "uses the R-7 algorithm to compute quantiles": function(quantile) {
+      var x = d3.scale.quantile().domain([3, 6, 7, 8, 8, 10, 13, 15, 16, 20]).range([0, 1, 2, 3]);
+      assert.deepEqual([3, 6, 6.9, 7, 7.1].map(x), [0, 0, 0, 0, 0]);
+      assert.deepEqual([8, 8.9].map(x), [1, 1]);
+      assert.deepEqual([9, 9.1, 10, 13].map(x), [2, 2, 2, 2]);
+      assert.deepEqual([14.9, 15, 15.1, 16, 20].map(x), [3, 3, 3, 3, 3]);
+      var x = d3.scale.quantile().domain([3, 6, 7, 8, 8, 9, 10, 13, 15, 16, 20]).range([0, 1, 2, 3]);
+      assert.deepEqual([3, 6, 6.9, 7, 7.1].map(x), [0, 0, 0, 0, 0]);
+      assert.deepEqual([8, 8.9].map(x), [1, 1]);
+      assert.deepEqual([9, 9.1, 10, 13].map(x), [2, 2, 2, 2]);
+      assert.deepEqual([14.9, 15, 15.1, 16, 20].map(x), [3, 3, 3, 3, 3]);
+    },
+    "domain values are sorted in ascending order": function(quantile) {
+      var x = d3.scale.quantile().domain([6, 3, 7, 8, 8, 13, 20, 15, 16, 10]);
+      assert.deepEqual(x.domain(), [3, 6, 7, 8, 8, 10, 13, 15, 16, 20]);
+    },
+    "non-numeric domain values are ignored": function(quantile) {
+      var x = d3.scale.quantile().domain([6, 3, NaN, undefined, 7, 8, 8, 13, 20, 15, 16, 10, NaN]);
+      assert.deepEqual(x.domain(), [3, 6, 7, 8, 8, 10, 13, 15, 16, 20]);
+    },
+    "quantiles returns the inner thresholds": function(quantile) {
+      var x = d3.scale.quantile().domain([3, 6, 7, 8, 8, 10, 13, 15, 16, 20]).range([0, 1, 2, 3]);
+      assert.deepEqual(x.quantiles(), [7.25, 9, 14.5]);
+      var x = d3.scale.quantile().domain([3, 6, 7, 8, 8, 9, 10, 13, 15, 16, 20]).range([0, 1, 2, 3]);
+      assert.deepEqual(x.quantiles(), [7.5, 9, 14]);
+    },
+    "range cardinality determines the number of quantiles": function(quantile) {
+      var x = d3.scale.quantile().domain([3, 6, 7, 8, 8, 10, 13, 15, 16, 20]);;
+      assert.deepEqual(x.range([0, 1, 2, 3]).quantiles(), [7.25, 9, 14.5]);
+      assert.deepEqual(x.range([0, 1]).quantiles(), [9]);
+      assert.deepEqual(x.range([,,,,,]).quantiles(), [6.8, 8, 11.2, 15.2]);
+      assert.deepEqual(x.range([,,,,,,]).quantiles(), [6.5, 8, 9, 13, 15.5]);
+    },
+    "range values are arbitrary": function(quantile) {
+      var a = new Object(), b = new Object(), c = new Object();
+      var x = d3.scale.quantile().domain([3, 6, 7, 8, 8, 10, 13, 15, 16, 20]).range([a, b, c, a]);
+      assert.deepEqual([3, 6, 6.9, 7, 7.1].map(x), [a, a, a, a, a]);
+      assert.deepEqual([8, 8.9].map(x), [b, b]);
+      assert.deepEqual([9, 9.1, 10, 13].map(x), [c, c, c, c]);
+      assert.deepEqual([14.9, 15, 15.1, 16, 20].map(x), [a, a, a, a, a]);
+    }
+  }
+});
+
+suite.export(module);