var vows = require("vows"),

load = require("../load"),

assert = require("../assert");

var suite = vows.describe("d3.median");

suite.addBatch({

"median": {

topic: load("arrays/median").expression("d3.median"),

"returns the median value for numbers": function(median) {

assert.equal(median([1]), 1);

assert.equal(median([5, 1, 2, 3, 4]), 3);

assert.equal(median([20, 3]), 11.5);

assert.equal(median([3, 20]), 11.5);

},

"ignores null, undefined and NaN": function(median) {

assert.equal(median([NaN, 1, 2, 3, 4, 5]), 3);

assert.equal(median([1, 2, 3, 4, 5, NaN]), 3);

assert.equal(median([10, null, 3, undefined, 5, NaN]), 5);

},

"can handle large numbers without overflowing": function(median) {

assert.equal(median([Number.MAX_VALUE, Number.MAX_VALUE]), Number.MAX_VALUE);

assert.equal(median([-Number.MAX_VALUE, -Number.MAX_VALUE]), -Number.MAX_VALUE);

},

"returns undefined for empty array": function(median) {

assert.isUndefined(median([]));

assert.isUndefined(median([null]));

assert.isUndefined(median([undefined]));

assert.isUndefined(median([NaN]));

assert.isUndefined(median([NaN, NaN]));

},

"applies the optional accessor function": function(median) {

assert.equal(median([[1, 2, 3, 4, 5], [2, 4, 6, 8, 10]], function(d) { return median(d); }), 4.5);

assert.equal(median([1, 2, 3, 4, 5], function(d, i) { return i; }), 2);

}

}

});

suite.export(module);