  @Test
  public void testMinInColumns() {

    final double[] expectedMinValues = new double[] {-1.00, 0, 0.50, -7.00};

    final int[] expectedMinIndices = new int[] {0, 0, 1, 2};

    final double[] actualMinValues = new double[4];
    final int[] actualMinColumnIndices =
        MatrixUtils.minInColumns(nonZeroColumnMatrix(), null, actualMinValues);

    assertThat(actualMinColumnIndices).isEqualTo(expectedMinIndices);
    assertThat(actualMinValues).isEqualTo(expectedMinValues);
  }