mathjs/test/unit-tests/function/matrix/concat.test.js

import assert from 'assert'
import math from '../../../../src/defaultInstance.js'
const bignumber = math.bignumber

describe('concat', function () {
  const a = [[1, 2], [3, 4]]
  const b = [[5, 6], [7, 8]]
  const c = [[9, 10], [11, 12]]
  const d = [
    [[1, 2], [3, 4]],
    [[5, 6], [7, 8]]
  ]
  const e = [
    [[9, 10], [11, 12]],
    [[13, 14], [15, 16]]
  ]

  it('should concatenate compatible matrices on the last dimension by default', function () {
    assert.deepStrictEqual(math.concat([1, 2, 3], [4, 5]), [1, 2, 3, 4, 5])
    assert.deepStrictEqual(math.concat(
      [bignumber(1), bignumber(2), bignumber(3)],
      [bignumber(4)]),
    [bignumber(1), bignumber(2), bignumber(3), bignumber(4)])
    assert.deepStrictEqual(math.concat([[1], [2], [3]], [[4]], 0), [[1], [2], [3], [4]])
    assert.deepStrictEqual(math.concat([[], []], [[1, 2], [3, 4]]), [[1, 2], [3, 4]])

    assert.deepStrictEqual(math.concat(math.matrix(a), math.matrix(b)), math.matrix([
      [1, 2, 5, 6],
      [3, 4, 7, 8]
    ]))

    assert.deepStrictEqual(math.concat(a, b, c), [
      [1, 2, 5, 6, 9, 10],
      [3, 4, 7, 8, 11, 12]
    ])

    assert.deepStrictEqual(math.concat(d, e), [
      [[1, 2, 9, 10], [3, 4, 11, 12]],
      [[5, 6, 13, 14], [7, 8, 15, 16]]
    ])
  })

  it('should concatenate compatible matrices on the given dimension', function () {
    assert.deepStrictEqual(math.concat([[1]], [[2]], 1), [[1, 2]])
    assert.deepStrictEqual(math.concat([[1]], [[2]], 0), [[1], [2]])
    assert.deepStrictEqual(math.concat([[1]], [[2]], 0), [[1], [2]])

    assert.deepStrictEqual(math.concat(a, b, 0), [
      [1, 2],
      [3, 4],
      [5, 6],
      [7, 8]
    ])

    assert.deepStrictEqual(math.concat(a, b, c, 0), [
      [1, 2],
      [3, 4],
      [5, 6],
      [7, 8],
      [9, 10],
      [11, 12]
    ])

    assert.deepStrictEqual(math.concat(d, e, 0), [
      [[1, 2], [3, 4]],
      [[5, 6], [7, 8]],
      [[9, 10], [11, 12]],
      [[13, 14], [15, 16]]
    ])

    assert.deepStrictEqual(math.concat(d, e, 1), [
      [[1, 2], [3, 4], [9, 10], [11, 12]],
      [[5, 6], [7, 8], [13, 14], [15, 16]]
    ])

    assert.deepStrictEqual(math.concat(d, e, bignumber(1)), [
      [[1, 2], [3, 4], [9, 10], [11, 12]],
      [[5, 6], [7, 8], [13, 14], [15, 16]]
    ])
  })

  it('should concatenate strings', function () {
    assert.strictEqual(math.concat('a', 'b'), 'ab')
    assert.strictEqual(math.concat('a', 'b', 'c'), 'abc')
  })

  it('should throw an error in case of invalid requested dimension number', function () {
    assert.throws(function () { math.concat([1, 2], [3, 4], 2.3) }, /Integer number expected for dimension/)
    assert.throws(function () { math.concat([1, 2], [3, 4], 1) }, /Index out of range \(1 > 0\)/)
  })

  it('should throw an error in case dimension mismatch', function () {
    assert.throws(function () { math.concat([1, 2], [[1, 2], [3, 4]]) }, RangeError)
    assert.throws(function () { math.concat([[1, 2]], [[1, 2], [3, 4]]) }, /Dimension mismatch/)
  })

  it('should throw an error in case of invalid type of argument', function () {
    assert.throws(function () { math.concat(math.complex(2, 3)) }, /TypeError: Unexpected type of argument/)
  })

  it('should throw an error when called without matrices as argument', function () {
    assert.throws(function () { math.concat(2) }, /At least one matrix expected/)
  })

  it('should LaTeX concat', function () {
    const expression = math.parse('concat([1],[2])')
    assert.strictEqual(expression.toTex(), '\\mathrm{concat}\\left(\\begin{bmatrix}1\\\\\\end{bmatrix},\\begin{bmatrix}2\\\\\\end{bmatrix}\\right)')
  })
})