@Test
public void testMaxInColumns() {

  final double[] expectedMaxValues = new double[] {0.00, 5.00, 5.00, 19.00};
  final int[] expectedMaxIndices = new int[] {1, 2, 2, 1};
  final double[] actualMaxValues = new double[4];
  final int[] actualMaxColumnIndices =
      MatrixUtils.maxInColumns(nonZeroColumnMatrix(), null, actualMaxValues);
  assertThat(actualMaxColumnIndices).isEqualTo(expectedMaxIndices);
  assertThat(actualMaxValues).isEqualTo(expectedMaxValues);
}