mathjs/test/function/matrix/subset.test.js

var assert = require('assert'),
    math = require('../../../index.js'),
    subset = math.subset,
    matrix = math.matrix,
    range = math.range,
    index = math.index;

describe('subset', function() {

  var a = [[1,2], [3,4]];
  var b = math.matrix(a);

  it('should get the right subset of an array', function() {
    assert.deepEqual(subset(a, index([0,2], 1)), [[2],[4]]);
    assert.deepEqual(subset(a, index(1,0)), 3);
  });

  it('should throw an error if trying to access an invalid subset of an array', function() {
    assert.throws(function () {subset(a, index(6, 0))}, RangeError);
    assert.throws(function () {subset(a, index(1))}, RangeError);
    assert.throws(function () {subset(a, index(1,0,0))}, RangeError);
    assert.throws(function () {subset(a, index(1.3, 0))}, TypeError);
  });

  it('should get the right subset of a matrix', function() {
    assert.deepEqual(subset(b, index([0,2], 1)), matrix([[2],[4]]));
    assert.deepEqual(subset(b, index(1, 0)), 3);
  });

  it('should throw an error if trying to access an invalid subset of a matrix', function() {
    assert.throws(function () {subset(b, index(6, 0))}, RangeError);
    assert.throws(function () {subset(b, index(1))}, RangeError);
    assert.throws(function () {subset(b, index(1,0,0))}, RangeError);
    assert.throws(function () {subset(b, index(1.3, 0))}, TypeError);
  });

  it('should get the right subset of a string', function() {
    assert.deepEqual(subset('hello', index(1)), 'e');
    assert.deepEqual(subset('hello', index([4,-1,-1])), 'olleh');
  });

  it('should throw an error if trying to access an invalid subset of a string', function() {
    assert.throws(function () {subset('hello', 1)}, TypeError);
    assert.throws(function () {subset('hello', index([6]))}, SyntaxError);
    assert.throws(function () {subset('hello', index([-2]))}, SyntaxError);
    assert.throws(function () {subset('hello', index([1.3]))}, TypeError);
  });

  it('should get the right subset of a number', function() {
    assert.deepEqual(subset(123, index(0)), 123);
  });

  it('should get the right subset of a complex number', function() {
    assert.deepEqual(subset(math.complex('2+3i'), index(0)), math.complex(2,3));
  });

  it('should throw an error if trying to access an invalid subset for a number', function() {
    assert.throws(function () {subset(123, index(1))}, RangeError);
    assert.throws(function () {subset(123, index(-1))}, RangeError);
    assert.throws(function () {subset(123, index(-2))}, RangeError);
    assert.throws(function () {subset(123, index(1,2))}, RangeError);
    assert.throws(function () {subset(123, index(0,0))}, RangeError); // TODO: this should be supported
    assert.throws(function () {subset(123, index(2.4))}, TypeError);
  });

  var d = [[1,2], [3,4]];
  var g  = matrix([[1,2], [3,4]]);

  it('should set the right subset of an array', function() {
    assert.deepEqual(d, [[1,2], [3,4]]);
    assert.deepEqual(subset(d, index([0,2], 1), [[-2],[-4]]), [[1,-2], [3,-4]]);
    assert.deepEqual(d, [[1,2], [3,4]]);
    assert.deepEqual(subset(d, index(2, [0,2]), [[5,6]]), [[1,2], [3,4], [5,6]]);
    assert.deepEqual(d, [[1,2], [3,4]]);
    assert.deepEqual(subset(d, index(0,0), 123), [[123,2], [3,4]]);
  });

  it('should throw an error if setting the subset of an array with an invalid replacement', function() {
    assert.throws(function () {subset(d, index(1), 123)}, RangeError);
    assert.throws(function () {subset(d, index(1.3,0), 123)}, TypeError);
  });

  it('should set the right subset of a matrix', function() {
    assert.deepEqual(g, matrix([[1,2], [3,4]]));
    assert.deepEqual(subset(g, index([0,2], 1), [[-2],[-4]]), matrix([[1,-2], [3,-4]]));
    assert.deepEqual(g, matrix([[1,2], [3,4]]));
    assert.deepEqual(subset(g, index(2, [0,2]), [[5,6]]), matrix([[1,2], [3,4], [5,6]]));
  });

  it('should throw an error if setting the subset of a matrix with an invalid replacement', function() {
    assert.throws(function () {subset(d, index(1), 123)}, RangeError);
    assert.throws(function () {subset(d, index(1.3,0), 123)}, TypeError);
  });

  it('should set the right subset of a string', function() {
    var j = 'hello';
    assert.deepEqual(subset(j, index(0), 'H'), 'Hello');
    assert.deepEqual(j, 'hello');
    assert.deepEqual(subset(j, index(5), '!'), 'hello!');
    assert.deepEqual(j, 'hello');
    assert.deepEqual(subset(j, index([5,11]), ' world'), 'hello world');
    assert.deepEqual(j, 'hello');
  });

  it('should throw an error if setting the subset of a string with an invalid replacement', function() {
    assert.throws(function () {subset('hello', index([1,2]), '1234')}, RangeError);
    assert.throws(function () {subset('hello', index(1,2), 'a')}, RangeError);
  });

  it('should set the right subset of a number', function() {
    assert.deepEqual(subset(123, index(0), 456), 456);
    assert.deepEqual(subset(123, index(0,0), 456), 456);
    assert.deepEqual(subset(123, index(1), 456), [123, 456]);
  });

  it('should throw an error if setting the subset of a number with invalid replacement', function() {
    assert.throws(function () {subset(123, index(-1), 456)}, RangeError);
    assert.throws(function () {subset(123, index(-2), 456)}, RangeError);
    assert.throws(function () {subset(123, index(2.4), 456)}, TypeError);
  });

  it('should set the right subset of a complex number', function() {
    assert.deepEqual(subset(math.complex('2+3i'), index(0), 123), 123);
  });

  /*
  it('should parse subset operations correctly', function() {
    var parser = math.parser();
    assert.deepEqual(parser.eval('a = [1,2;3,4]'), matrix([[1,2],[3,4]]));
    assert.deepEqual(parser.eval('a(1,1)'), 4);
    assert.deepEqual(parser.eval('a(:,1)'), matrix([[2],[4]]));
    assert.deepEqual(parser.eval('a(:,1) = [-2;-4]'), matrix([[1,-2],[3,-4]]));
    assert.deepEqual(parser.eval('b=123'), 123);
    assert.deepEqual(parser.eval('b(0)'), 123);
    // assert.deepEqual(parser.eval('b(0,0)'), 123); // TODO: should be supported?
    assert.deepEqual(parser.eval('b(0)=456'), 456);
    assert.deepEqual(parser.eval('b'), 456);
    assert.deepEqual(parser.eval('c="hello"'), "hello");
    assert.deepEqual(parser.eval('c(1:4)'), "ell");
    assert.deepEqual(parser.eval('c(0) = "H"'), "Hello");
    assert.deepEqual(parser.eval('c'), "Hello");
    assert.deepEqual(parser.eval('c(5:11) = " world"'), "Hello world");
    assert.deepEqual(parser.eval('c(4:-1:-1)'), "olleH");
    assert.deepEqual(parser.eval('c(end-1:-1:-1)'), "dlrow olleH");
  });
*/
});