public void ShouldExtractMatrix2() { //Arrange var matrix = new DenseMatrix(new double[,] { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } }); //Act var extracted = matrix.Extract(new[] { 1 }, new[] { 2 }); //Assert AreEqual(1, extracted.ColumnCount); AreEqual(1, extracted.RowCount); AreEqual(new[] { 6.0 }, extracted.Row(0)); }