Program sffedchain21 | Fast explicit diffusion using chains - linear operator (2-D) 
[SYNOPSIS]
sffedchain21 < inp.rsf weight=wht.rsf sig=sig.rsf > out.rsf adj=n
[PARAMETERS]
bool    | adj | =n |  [y/n] | 	adjoint flag 
file    | sig | = |   | 	auxiliary input file name
file    | weight | = |   | 	auxiliary input file name
[DIRECTORY]
user/fomels
