*
* Example MICRO.DAT from pp 647-648
*
open data micro.dat
data(format=free,org=columns) 1 7 year density linear
*
graph
# density
*
* Gompertz curve
*
set ytrans = log(log(1200/density))
linreg ytrans
# constant year
compute a=exp(%beta(1))
set fitfore 1 20 = 1200*exp(-a*exp(%beta(2)*t))
set error = density-fitfore
*
print(picture="*.##") / density fitfore error