* Gauss Chapter
drop _all

use lbw, clear
regress bwt lwt race2 race3 smoke ht ui

glm bwt lwt race2 race3 smoke ht ui

glm bwt lwt race2 race3 smoke ht ui, irls

insheet using beta.txt, clear
gen female = sex==2
gen pills  = vitamin==1 | vitamin==2
glm betap age female pills kcal fat fiber alcohol chol betad
predict double res, pearson
hist res

hist res
graph export gausshistres.eps, replace

sort res
gen nscore = invnormal(_n/316)
twoway scatter nscore res
twoway scatter res kcal, yline(0)

twoway scatter nscore res
graph export gaussnscore.eps, replace
twoway scatter res kcal, yline(0)
graph export gaussreskcal.eps, replace

drop if kcal > 4000
glm betap age female pills kcal fat fiber alcohol chol betad, link(log) nolog
predict double betaphat, mu
predict double resloglink, pearson
hist resloglink
twoway scatter resloglink betaphat, yline(0)

hist resloglin
graph export gausshistresloglink.eps, replace
twoway scatter resloglink betaphat, yline(0)
graph export gaussresidplot.eps, replace

gen double logbetap = log(betap)
glm logbetap age female pills kcal fat fiber alcohol chol betad
predict double logbetaphat, mu
predict double reslognormal, pearson
hist reslognormal

hist reslognormal
graph export gausshistrespearson.eps, replace

twoway scatter reslognormal logbetaphat, yline(0)

sort reslognormal
gen nscorelb = invnormal(_n/315)
twoway scatter nscorelb reslognormal || line reslognormal reslognormal 
twoway scatter reslognormal kcal, yline(0)

twoway scatter reslognormal logbetaphat, yline(0)
graph export gausspresid.eps, replace
twoway scatter nscorelb reslognormal || line reslognormal reslognormal 
graph export gaussnscorelogbeta.eps, replace
twoway scatter reslognormal kcal, yline(0)
graph export gaussreslogbetakcal.eps, replace