Sage Reference Manual: Matrices and Spaces of Matrices - Mirrors

Sage Reference Manual: Matrices and Spaces of Matrices, Release 6.1.1
[ 1 1 0 2 2]
[ 1 0 1 1 4]
[-1 2 -2 -1 4]
Set the 2 x 3 submatrix of M starting at row index and column index 1:
sage: M[1:3,[1..3]] = M[2:4,0:3]; M
[ 1 -2 -1 -1 9]
[ 1 1 0 1 2]
[ 1 -1 2 -2 4]
[-1 2 -2 -1 4]
Set part of the first column of M:
sage: M[1:,0]=[[2],[3],[4]]; M
[ 1 -2 -1 -1 9]
[ 2 1 0 1 2]
[ 3 -1 2 -2 4]
[ 4 2 -2 -1 4]
Or do a similar thing with a vector:
sage: M[1:,0]=vector([-2,-3,-4]); M
[ 1 -2 -1 -1 9]
[-2 1 0 1 2]
[-3 -1 2 -2 4]
[-4 2 -2 -1 4]
Or a constant:
sage: M[1:,0]=30; M
[ 1 -2 -1 -1 9]
[30 1 0 1 2]
[30 -1 2 -2 4]
[30 2 -2 -1 4]
Set the first row of M:
sage: M[0,:]=[[20,21,22,23,24]]; M
[20 21 22 23 24]
[30 1 0 1 2]
[30 -1 2 -2 4]
[30 2 -2 -1 4]
sage: M[0,:]=vector([0,1,2,3,4]); M
[ 0 1 2 3 4]
[30 1 0 1 2]
[30 -1 2 -2 4]
[30 2 -2 -1 4]
sage: M[0,:]=-3; M
[-3 -3 -3 -3 -3]
[30 1 0 1 2]
[30 -1 2 -2 4]
[30 2 -2 -1 4]
sage: A = matrix(ZZ,3,4, [3, 2, -5, 0, 1, -1, 1, -4, 1, 0, 1, -3]); A
[ 3 2 -5 0]
[ 1 -1 1 -4]
[ 1 0 1 -3]
62 Chapter 3. Matrices over an arbitrary ring