You may alter an array using slices or by direct access. The following changes only one element in a 
matrix 
:
M[1, 2] = 2.0 # scalar
Also, we may change one full row of the matrix:
M[2, :] = [1., 2., 3.] # vector
Similarly, we may also replace a full submatrix:
M[1:3, :] = array([[1., 2., 3.],[-1.,-2., -3.]])
There is a distinction between a column matrix and a vector. The following assignment with a column matrix returns no error:
M[1:4, 1:2] = array([[1.],[0.],[-1.0]])
while the assignment with a vector returns a ValueError:
M[1:4, 1:2] = array([1., 0., -1.0]) # error
The general slicing rules are shown in Table 4.3. The matrices and vectors in the preceding examples must have the right size to fit into matrix 
. You may also make use of the broadcasting rules (see Section 5.5: Broadcasting) to determine the allowed size of the replacement arrays. If the replacement array does not have...
