if "`c(os)'" == "Unix" {
  cd ~/pdrive/home/teaching/stats/11_Stata_2
}
else {
  cd p:/home/teaching/stats/11_Stata_2
}
sjlog using solution, replace
set more off
clear 

sysuse uslifeexp, clear
twoway scatter le year
graph export graph1.eps, replace
twoway scatter le year, title("U.S. Life Expectancy")
graph export graph2.eps, replace
twoway scatter le year, title("U.S. Life Expectancy") ylabel(0(20)80)
graph export graph3.eps, replace
twoway scatter le_male year || scatter le_female year
graph export graph4.eps, replace
twoway scatter le_male year || scatter le_female year || lfitci	    /* 
*/     le_male year || lfitci le_female year
graph export graph5.eps, replace
twoway scatter le_male year || scatter le_female year || lfitci	    /* 
*/     le_male year || lfitci le_female year, ytitle("Life Expecancy")
graph export graph6.eps, replace

sysuse cancer, clear
describe
* 2.1 There are 48 observations
codebook
* 2.2 the longest followup time is 39 months
* 2.3 There were 3 different treatments in the study (1 being a placebo)
* 2.4 The ages ranged from 47 to 67
* 2.5 The mean age at the start of the study was 55.875
* 2.6 The SD of the followup time was 10.26
tab drug died, row
* 2.7 19 subjects on placebo died
* 2.8 43% of subjects on treatment 2 died
summarize age if died == 1
* 3.1 Mean age = 56.8
summarize age if drug == 1
* 3.2 Mean age of those on placebo = 56.1
summarize age if drug == 1 & died == 1
* 3.3 Mean age of those on placebo who died = 55.9
bysort died: summ age
bysort drug: summ age
bysort drug died: summ age
egen agegrp = cut(age), group(2)
bysort agegrp: summ age
* 3.4 The group would be split at the median age, which according to codebook was 56
label define agegrp 0 "47-55" 1 "56-67"
label values agegrp agegrp
tab agegrp died
bysort agegrp: gen group_size = _N
tab group_size
save mycancer, replace

foreach x in one two three {
display " `x' "
}
foreach x in drug agegrp {
tab `x' died, row
}
sysuse uslifeexp
foreach x of varlist le* {
twoway scatter `x' year, name("`x'")
}
graph export graph7.eps, replace
sysuse bplong
bysort when: summ bp
* Mean BP before 156.45, after 151.36
reshape wide bp, i(patient) j(when)
summ bp1 bp2
sysuse uslifeexp, clear
rename le le_total
reshape long le, i(year) j(group) string
tab group
twoway scatter le year if group == "_male" || scatter le year if group == "_female"
graph export graph8.eps, replace
sjlog close, replace