assertEquals(0, a.viewPart(0, 3, 1, 3).viewDiagonal().minus(
new DenseVector(new double[]{2, 6, 9})).norm(1), 1.0e-10);
assertEquals(4, a.get(0, 3), 1.0e-10);
print(a);
Matrix m = new DenseMatrix(4, 4).assign(a);
assertEquals(0, m.minus(a).aggregate(Functions.PLUS, Functions.ABS), 1.0e-10);
print(m);
assertEquals(0, m.transpose().times(m).minus(a.transpose().times(a)).aggregate(
Functions.PLUS, Functions.ABS), 1.0e-10);
assertEquals(0, m.plus(m).minus(a.plus(a)).aggregate(Functions.PLUS, Functions.ABS), 1.0e-10);