b=matrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]])
d=4*b
d
c=matrix([[1,1,1,1],[1,1,1,1],[1,1,1,1],[1,1,1,1]])
c
A=d-c;A
A*matrix([[1],[1],[1],[1]])

Strang-ex-1.6-33-U (last edited 2010-12-17 12:20:50 by prasad)