reset data
reset plot control
reset i/o
dimension 500 30
label size 3
set read format f1.0,f6.0,f8.0,32x,f10.4,f10.4
read mpc633a.dat run wafer probe y sr
retain run wafer probe y sr subset probe 2362
sd plot y wafer subset run 1
let s21 = yplot
let wafer1 = xplot
sd plot y wafer subset run 2
let s22 = yplot
retain s21 s22 wafer1 subset tagplot = 1
let nwaf = size wafer1
let df21 = 5 for i = 1 1 nwaf
let df22 = 5 for i = 1 1 nwaf
let s2a = (s21**2)/5 + (s22**2)/5
let s2 = sum s2a
let s2 = sqrt(s2/2) 
let df2a = df21 + df22
let df2 = sum df2a
. pooled level-2 standard deviation and df across wafers and runs
print s2 df2
. end of calculations