Add method to manipulate columns and rows of Matrix objects
In this moment, a method to extract or modify only specific rows of a Matrix is missing. It would be nice, for instance, to write
U = zeros(2,10)
U[:,0] = Matrix([[e],
[5]])
for k in range(U.width-1):
U[:,k+1] = 5 * U[:,k]
to define an input signal increasing by 5 for all k
.