u:
        0         2         4 
M=
        0         0         0 
        0         0         0 
        0         0         0 
        0         0         0 
        0         0         0 
M=
        0         0         0 
        0         2         0 
        0         4         0 
        0         0         0 
        0         0         0 
v:

        0         2         4 
u:
 
        0         2         4 
u+v:

        0         4         8 
M=

        0         1         2 
        1         2         3 
        2         3         4 
        3         4         5 
        4         5         6 
M+M=

        0         2         4 
        2         4         6 
        4         6         8 
        6         8        10 
        8        10        12 
(M+M)/10=

        0       0.2       0.4 
      0.2       0.4       0.6 
      0.4       0.6       0.8 
      0.6       0.8         1 
      0.8         1       1.2 
m1=

        1         2         3         4         5 
M.col(1)

        1         2         3         4         5 
w=	
        0         0         0         0         0 
w=	
        0       666         0         0         0 
M=

        0         0         2 
        1      13.3         3 
        2         0         4 
        3         0         5 
        4         0         6