def real r s rw sw w 
def real n nw 
let r 0 
let s 0 
let rw 0 
let sw 0 
let n 0 
let nw 0 
for i 1 to 64 
  for j 1 to 64 
    if &1[i,j,2].ne.0 then 
      let r r+&1[i,j,2] 
      let s s+&1[i,j,2]^2 
      let n n+1 
      let w &1[i,j,3] 
      if w.ne.0 then 
        let w 10**(w|10.) 
        let rw rw+&1[i,j,2]*w 
        let sw sw+&1[i,j,2]^2*w 
        let nw nw+w 
      endif 
    endif 
  next 
next 
let s s|n 
let r r|n 
let rms sqrt(s-r^2) 
let sw sw|nw 
let rw rw|nw 
let rms sqrt(s-r^2) 
let rmsw sqrt(sw-rw^2) 
say "RMS (unweighted)  = " 'rms' "RMS (weighted)  = " 'rmsw'