Absolute value

hi, i need to get the Absolute value of this:

f=(vv(1,1)-vv(1,2,1,m))+(vv(1,1)-vv(1,2,1,m))+(vv(2,1)-vv(2,2,1,m))+(vv(3,1)-vv(3,2,1,m))+(vv(4,1)-vv(4,2,1,m))+....

i need to do a sum(from 1 to 22) of absolute values of the difference -> vv(x,y)-vv(x,y,w,z)

how can i make that?

Answer 1

[William]

Can you define "vv"? If it is composed of real numbers

fabs = abs(f)