# PS3.6 for application section 3.11 
open data3-3
ols PATENTS const R_D 
# save residuals 
genr ut = $uhat
# compute fitted values 
genr temp = PATENTS - ut
# round to one decimal 
genr fitted =int(0.5+(10*temp))/10
# compute forecast error 
genr error = PATENTS - fitted
# compute absolute % error 
genr abspcerr = int(0.5+(10000*abs(error)/PATENTS))/100
# print values; see Table 3.5 
print -o R_D PATENTS fitted error abspcerr