wilson - wilson's factorization
call wilson_init(nmax)
call wilson_factor(niter,s0,ss,a0,aa)
call wilson_close()
maximum number of space needed (n1*10 good number)
zero lag value of input
type(filter)
auto correlation
Output zero lag value
type(filter)
Minimum phase filter
Find a minumum phase filter with the given auto-correaltion function
the cross_wilson manpage,the lapfac manpage
geef90