reset data
reset plot control
reset i/o
dimension 500 rows
label size 3
. set read format f1.0,f6.0,f8.0,f8.0,f8.0,f8.0,f8.2,f10.4,f10.4
set read format f1.0,f6.0,f8.0,32x,f10.4
. read mpc61.dat run wafer probe mo day op hum y sr
read mpc61.dat run wafer probe y
retain run wafer probe y 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 s21
let df21 = 5 for i = 1 1 nwaf
let df22 = 5 for i = 1 1 nwaf
. level-2 standard deviations and df for 5 wafers - run 1
print "level-2 standard deviations and df for 5 wafers - run 1"
print wafer1 s21 df21
.
. level-2 standard deviations and df for 5 wafers - run 2
print "level-2 standard deviations and df for 5 wafers - run 2"
print wafer1 s22 df22
.
let stemp = (s21**2 + s22**2)/nwaf
let ssum = sum stemp
let s2 = sqrt(ssum/2)
let dtemp = df21 + df22
let df2 = sum dtemp
. pooled level-2 standard deviation and df across wafers and runs
print s2 df2
. end of calculations