java multi-dimensional array transposing

Question

I have a row-based multidimensional array:

/** [row][column]. */
public int[][] tiles;

I would like to transform this array to column-based

Answer 1

Here is my 50 cents: a utility method and test to transponse multidimensional array (for doubles in my case):

/**
  * Transponse bidimensional array.
  *
  * @param original Original table.
  * @return Transponsed.
  */
public static double[][] transponse(double[][] original) {

double[][] transponsed = new double
    [original[0].length]
    [original.length];

  for (int i = 0; i < original[0].length; i++) {

    for (int j = 0; j < original.length; j++) {

      transponsed[i][j] = original[j][i];
    }
  }

  return transponsed;
}


@Test
void aMatrix_OfTwoDimensions_ToBeTransponsed() {

  final double[][] original =
    new double[][] { { 1, 2, 3, 4 }, { 5, 6, 7, 8 }, { 9, 10, 11, 12 } };

  double[][] transponsed = Analysis.transponse(original);

  assertThat(transponsed[1][2], is(equalTo(10)));
}