mathjs/test/type/matrix/Index.test.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser and offers an integrated solution to work with numbers, big numbers, complex numbers, units, and matrices.

// test data type Index
var assert = require('assert');
var math = require('../../../index');
var Index = math.type.Index;
var Range = math.type.Range;
var ImmutableDenseMatrix = math.type.ImmutableDenseMatrix;

describe('Index', function () {

  it('should create an Index', function () {
    assert.deepEqual(new Index(0, 2)._dimensions, [new ImmutableDenseMatrix([0]), new ImmutableDenseMatrix([2])]);

    assert.deepEqual(new Index(new Range(0, 10))._dimensions, [{start:0, end:10, step:1}]);
    assert.deepEqual(new Index(new Range(0, 10, 2))._dimensions, [{start:0, end:10, step:2}]);
    assert.deepEqual(new Index(new Range(0, 10), new Range(4, 6))._dimensions, [
      {start:0, end:10, step:1},
      {start:4, end:6, step:1}
    ]);
    assert.deepEqual(new Index(new ImmutableDenseMatrix([0, 10]))._dimensions, [new ImmutableDenseMatrix([0, 10])]);
    assert.deepEqual(new Index([0, 10])._dimensions, [new ImmutableDenseMatrix([0, 10])]);
    assert.deepEqual(new Index(10)._dimensions, [new ImmutableDenseMatrix([10])]);
  });

  it('should create an Index from a Range', function () {
    assert.deepEqual(new Index(new Range(0, 10))._dimensions, [{start:0, end:10, step:1}]);
  });

  it('should create an Index from a Matrix', function () {
    assert.deepEqual(new Index(math.matrix([0, 10]))._dimensions, [new ImmutableDenseMatrix([0, 10])]);
  });
  
  it('should create an Index from an Array', function () {
    assert.deepEqual(new Index([0, 10])._dimensions, [new ImmutableDenseMatrix([0, 10])]);
  });

  it('should create an Index from a string', function () {
    assert.deepEqual(new Index('property')._dimensions, ['property']);
  });

  it('should create an Index from a ImmutableDenseMatrix', function () {
    assert.deepEqual(new Index(new ImmutableDenseMatrix([0, 10]))._dimensions, [new ImmutableDenseMatrix([0, 10])]);
  });

  it('should create an Index from an array with ranges', function () {
    var index = Index.create([new Range(0, 10), new Range(4)]);
    assert(index instanceof Index);
    assert.deepEqual(index._dimensions, [new Range(0, 10), new Range(4)]);
  });
  
  it('should create an Index from an array with sets', function () {
    var index = Index.create([new ImmutableDenseMatrix([0, 10]), new ImmutableDenseMatrix([4])]);
    assert(index instanceof Index);
    assert.deepEqual(index._dimensions, [new ImmutableDenseMatrix([0, 10]), new ImmutableDenseMatrix([4])]);
  });

  it('should calculate the size of an Index', function () {
    assert.deepEqual(new Index(new Range(0, 10)).size(), [10]);
    assert.deepEqual(new Index(new Range(0, 10, 2)).size(), [5]);
    assert.deepEqual(new Index(new Range(4, 0, -1)).size(), [4]);
    assert.deepEqual(new Index(new Range(0, 10), new Range(4, 6)).size(), [10, 2]);
    assert.deepEqual(new Index(new Range(0, 10), new Range(4, 6), new Range(3, -1, -1)).size(), [10, 2, 4]);
    assert.deepEqual(new Index(new Range(0, 0)).size(), [0]);
    assert.deepEqual(new Index(new Range(0, -1)).size(), [0]);
    assert.deepEqual(new Index([1, 2, 3]).size(), [3]);
    assert.deepEqual(new Index(math.matrix([1, 2, 3])).size(), [3]);
    assert.deepEqual(new Index(new ImmutableDenseMatrix([1, 2, 3])).size(), [3]);
    assert.deepEqual(new Index('property').size(), [1]);
    assert.deepEqual(new Index().size(), []);
  });

  it('should calculate the minimum values of an Index', function () {
    assert.deepEqual(new Index(new Range(2, 10)).min(), [2]);
    assert.deepEqual(new Index(new Range(4, 0, -1)).min(), [1]);
    assert.deepEqual(new Index(new Range(0, 10), new Range(4, 6)).min(), [0, 4]);
    assert.deepEqual(new Index(new Range(0, 10), new Range(4, 6), new Range(3, -1, -1)).min(), [0, 4, 0]);
    assert.deepEqual(new Index(2).min(), [2]);
    assert.deepEqual(new Index(new Range(0, 10), new ImmutableDenseMatrix([4, 6]), new Range(3, -1, -1)).min(), [0, 4, 0]);
    assert.deepEqual(new Index().min(), []);
    assert.deepEqual(new Index('property').min(), ['property']);
  });

  it('should calculate the maximum values of an Index', function () {
    assert.deepEqual(new Index(new Range(2, 10)).max(), [9]);
    assert.deepEqual(new Index(new Range(4, 0, -1)).max(), [4]);
    assert.deepEqual(new Index(new Range(0, 10), new Range(4, 6)).max(), [9, 5]);
    assert.deepEqual(new Index(new Range(0, 10), new Range(4, 6), new Range(3, -1, -1)).max(), [9, 5, 3]);
    assert.deepEqual(new Index(2).max(), [2]);
    assert.deepEqual(new Index(new Range(0, 10), new ImmutableDenseMatrix([4, 6]), new Range(3, -1, -1)).max(), [9, 6, 3]);
    assert.deepEqual(new Index('property').max(), ['property']);
    assert.deepEqual(new Index().max(), []);
  });

  it('should test whether an Index contains a scalar', function () {
    assert.equal(new Index(2, 5, 2).isScalar(), true);
    assert.equal(new Index(2).isScalar(), true);
    assert.equal(new Index([0,1,2], 2).isScalar(), false);
    assert.equal(new Index([3], [2]).isScalar(), true);
    assert.equal(new Index([0,1,2], [2]).isScalar(), false);
    assert.equal(new Index(new Range(2, 10)).isScalar(), false);
    assert.equal(new Index(new ImmutableDenseMatrix([2, 10])).isScalar(), false);
    assert.equal(new Index(new ImmutableDenseMatrix([2])).isScalar(), true);
    assert.equal(new Index(2, new Range(0, 4), 2).isScalar(), false);
    assert.equal(new Index(2, new ImmutableDenseMatrix([0, 4]), 2).isScalar(), false);
    assert.equal(new Index(new Range(0, 2), new Range(0, 4)).isScalar(), false);
    assert.equal(new Index(new ImmutableDenseMatrix([0, 2]), new ImmutableDenseMatrix([0, 4])).isScalar(), false);
    assert.deepEqual(new Index('property').isScalar(), true);
    assert.equal(new Index().isScalar(), true);
  });

  it('should clone an Index', function () {
    var index1 = new Index(2, new Range(0, 4), new ImmutableDenseMatrix([0, 2]));
    var index2 = index1.clone(0);

    assert.deepEqual(index1, index2);
    assert.notStrictEqual(index1, index2);
    assert.notStrictEqual(index1._dimensions[0], index2._dimensions[0]);
    assert.notStrictEqual(index1._dimensions[1], index2._dimensions[1]);
    assert.notStrictEqual(index1._dimensions[2], index2._dimensions[2]);
  });

  it('should stringify an index', function () {
    assert.equal(new Index().toString(), '[]');
    assert.equal(new Index(2, 3).toString(), '[[2], [3]]');
    assert.equal(new Index(2, 3, 1).toString(), '[[2], [3], [1]]');
    assert.equal(new Index(2, new Range(0, 3)).toString(), '[[2], 0:3]');
    assert.equal(new Index(new Range(0, 6, 2)).toString(), '[0:2:6]');
    assert.equal(new Index(new ImmutableDenseMatrix([0, 6, 2])).toString(), '[[0, 6, 2]]');
    assert.deepEqual(new Index('property').toString(), '["property"]');
  });

  it('toJSON', function () {
    assert.deepEqual(new Index(new Range(0, 10), 2, new ImmutableDenseMatrix([1, 2, 3])).toJSON(),
        {'mathjs': 'Index', dimensions: [
          new Range(0, 10, 1),
          new ImmutableDenseMatrix([2]),
          new ImmutableDenseMatrix([1, 2, 3])
        ]});
  });

  it('fromJSON', function () {
    var json = {dimensions: [
      new Range(0, 10, 1),
      new ImmutableDenseMatrix([2]),
      new ImmutableDenseMatrix([1, 2, 3])
    ]};
    var i1 = new Index(new Range(0, 10), 2, new ImmutableDenseMatrix([1, 2, 3]));

    var i2 = Index.fromJSON(json);
    assert.ok(i2 instanceof Index);
    assert.deepEqual(i2, i1);
  });

  it('should get the range for a given dimension', function () {
    var index = new Index(2, new Range(0, 8, 2), new Range(3,-1,-1), new ImmutableDenseMatrix([1, 2, 3]));

    assert(index.dimension(0) instanceof ImmutableDenseMatrix);
    assert.deepEqual(index.dimension(0), new ImmutableDenseMatrix([2]));

    assert(index.dimension(1) instanceof Range);
    assert.deepEqual(index.dimension(1), new Range(0, 8, 2));

    assert(index.dimension(2) instanceof Range);
    assert.deepEqual(index.dimension(2), new Range(3, -1, -1));
    
    assert(index.dimension(3) instanceof ImmutableDenseMatrix);
    assert.deepEqual(index.dimension(3), new ImmutableDenseMatrix([1, 2, 3]));
    
    assert.strictEqual(index.dimension(4), null);
  });

  it('should iterate over all ranges', function () {
    var index = new Index(2, new Range(0, 8, 2), new Range(3,-1,-1), [1, 2, 3]);

    var log = [];
    index.forEach(function (d, i, obj) {
      log.push({
        dimension: d,
        index: i
      });
      assert.strictEqual(obj, index);
    });

    assert.deepEqual(log, [
      {dimension: new ImmutableDenseMatrix([2]), index: 0},
      {dimension: new Range(0, 8, 2), index: 1},
      {dimension: new Range(3, -1, -1), index: 2},
      {dimension: new ImmutableDenseMatrix([1, 2, 3]), index: 3}
    ]);
  });

  it('should have a property isIndex', function () {
    var a = new math.type.Index([2, 5]);
    assert.strictEqual(a.isIndex, true);
  });

  it('should have a property type', function () {
    var a = new math.type.Index([2, 5]);
    assert.strictEqual(a.type, 'Index');
  });

  it('should test whether index contains an object property', function () {
    assert.strictEqual(new math.type.Index(2, 3).isObjectProperty(), false);
    assert.strictEqual(new math.type.Index([2, 5]).isObjectProperty(), false);
    assert.strictEqual(new math.type.Index('foo', 'bar').isObjectProperty(), false);
    assert.strictEqual(new math.type.Index('foo').isObjectProperty(), true);
  });

  it('should expand an index into an array', function () {
    assert.deepEqual(new Index(new Range(2, 5)).toArray(), [
      [2, 3, 4]
    ]);

    assert.deepEqual(new Index(new Range(2, 5), new Range(0, 8, 2), 2, new ImmutableDenseMatrix([1,2])).toArray(), [
      [2, 3, 4],
      [0, 2, 4, 6],
      [2],
      [1, 2]
    ]);

    assert.deepEqual(new Index(2, new Range(0, 8, 2), new Range(3,-1,-1), new Range(2, 4, 0), [1, 2]).toArray(), [
      [2],
      [0, 2, 4, 6],
      [3, 2, 1, 0],
      [],
      [1, 2]
    ]);

    assert.deepEqual(new Index('property').toArray(), ['property']);
  });

  it('valueOf should return the expanded array', function () {
    assert.deepEqual(new Index(2, new Range(0, 8, 2), new Range(3,-1,-1), [1, 2], new ImmutableDenseMatrix([3, 4])).valueOf(), [
      [2],
      [0, 2, 4, 6],
      [3, 2, 1, 0],
      [1, 2],
      [3, 4]
    ]);
  });

  it('should complain when new operator is missing', function () {
    assert.throws(function () {Index([2, 5]);}, /Constructor must be called with the new operator/);
  });

  it('should throw an error on non-integer ranges', function () {
    assert.throws(function () {new Index([0,4.5]);});
    assert.throws(function () {new Index([0.1,4]);});
    assert.throws(function () {new Index([4,2,0.1]);});
  });

  it('should throw an error on unsupported type of arguments', function () {
    assert.throws(function () {new Index({});}, TypeError);
    assert.throws(function () {new Index(new Date());}, TypeError);
  });
});