if "`c(os)'" == "Unix" {
  global home ~/pdrive/home/teaching/stats
}
else { 
  global home P:/home/teaching/stats
}
global filelist auto bpafter bpbefore bplong bpwide myauto myauto2 mybplong
cd "$home"
foreach file in $filelist {
  capture erase "datasets/`file'.dta"
}
// capture rmdir "datasets"

cd "$home/1_intro_to_stata"
sjlog using solution, replace
clear

* 2.1
global mydir $home/datasets
capture kdir $mydir 
cd $mydir

* 2.2
sysuse auto
save $mydir/auto
dir
clear
use auto
save myauto

* 2.3.1
generate wtkg = weight/2.2046
label variable wtkg "Weight (kg)"

* 2.3.2
generate short = 0
replace short = 1 if length < 190
generate short2 = (length < 190)
tab short short2

* 2.3.3
egen wtt = cut(weight), group(3)
label variable wtt "Tertiles of weight"
tab wtt
label def tertiles 0 "Lowest tertile" 1 "Middle tertile" 2 "Highest tertile"
label values wtt tertiles
tab wtt
tab make

* 2.3.4
gen str20 company = substr(make, 1, index(make, " "))
tab company
replace company = make if company == ""
save, replace

* 2.4
sysuse bplong
save $mydir/bplong
preserve
keep if when == 1
save $mydir/bpbefore
restore
keep if when == 2
save "$mydir/bpafter"

* 2.4.1
use bpbefore, clear
gen fromfile = 1
append using bpafter
replace fromfile = 2 if fromfile == .
tab fromfile when
label variable fromfile "Whether the measurement is a before or after"
label define fromfile 1 "Before" 2 "After"
label values fromfile fromfile

* 2.4.2
save mybplong
use bpbefore, clear
rename bp bp_before
save, replace
use bpafter
rename bp bp_after
save, replace
use bpbefore
sort patient
save, replace
use bpafter
sort patient
save, replace
merge patient using bpbefore
tab _merge
save bpwide

* 2.5.1
use myauto
gen lengthm = length*0.0254

* 2.5.2
gen heavy = weight > 3000 if weight < .
tab heavy

* 2.5.3
egen wtpt = cut(weight), group(3)
tab wtt wtpt

* 2.5.4
egen comp2 = ends(make), head
tab comp2
save myauto2

* 2.5.5
use bpwide
gen bpdiff = bp_after - bp_before

* 2.5.6
egen gsex = group(sex agegrp)
tab gsex
sjlog close, replace