text: var assert = require('assert');
  var approx = require('../../../tools/approx');
  var math = require('../../../index');
  var BigNumber = math.type.BigNumber;
  var DenseMatrix = math.type.DenseMatrix;
  var mad = math.mad;
  
  describe('mad', function() {
  
    it('should return the median absolute deviation of numbers', function() {
      assert.equal(mad(10), 0);
      assert.equal(mad(4,6,8), 2);
      assert.equal(mad(1, 10, 20, 30), 9.5);
    });
  
    it('should return the median absolute deviation of big numbers', function() {
      assert.deepEqual(mad(new BigNumber(4),new BigNumber(6),new BigNumber(8)),
        new BigNumber(2));
    });
  
    it('should return the median absolute deviation from an array', function() {
      assert.equal(mad([10]), 0);
      assert.equal(mad([4,6,8]), 2);
      assert.equal(mad([1, 10, 20, 30]), 9.5);
    });
  
    it('should return the median absolute deviation from an 1d matrix', function() {
      assert.equal(mad(new DenseMatrix([10])), 0);
      assert.equal(mad(new DenseMatrix([4,6,8])), 2);
      assert.equal(mad(new DenseMatrix([1, 10, 20, 30])), 9.5);
    });
  
    it('should return the median absolute deviation element from a 2d array', function() {
      assert.deepEqual(mad([
        [2,4,6],
        [1,3,5]
      ]), 1.5);
    });
  
    it('should return the median absolute deviation element from a 2d matrix', function() {
      assert.deepEqual(mad(new DenseMatrix([
        [2,4,6],
        [1,3,5]
      ])), 1.5);
    });
  
    it('should throw an error if called with invalid number of arguments', function() {
      assert.throws(function() {mad()});
    });
  
    it('should throw an error if called with an empty array', function() {
      assert.throws(function() {mad([])});
    });
  
    it('should LaTeX mad', function () {
      var expression = math.parse('mad(1,2,3)');
      assert.equal(expression.toTex(), '\\mathrm{mad}\\left(1,2,3\\right)');
    });
  
  });
  