public void testSlice() { DenseMatrix A = rand(5, 8); DenseMatrix B = rand(5, 12); DenseMatrix C = rand(4, 8); DenseMatrix AB = A.concatRight(B); assertTrue(A.equals(AB.cols(0, 8))); assertTrue(B.equals(AB.cols(8, 20))); DenseMatrix AC = A.concatDown(C); assertTrue(A.equals(AC.rows(0, 5))); assertTrue(C.equals(AC.rows(5, 9))); }