infile id site age male bkrace smoker estrogen prevdis ///
	diab2 bmi aai cholest crp fib ttodth death cvddth  ///
	using http://www.emersonstatistics.com/datasets/inflamm.txt
	
twoway (scatter fib crp if prevdis==1, jitter(2) col(blue)) ///
    (lowess fib crp if prevdis==1, col(blue)) ///
    (scatter fib crp if prevdis==0, jitter(1) col(pink) msymb(D)) ///
    (lowess fib crp if prevdis==0, col(pink)) ///
	(lowess fib crp, col(black) xtitle("C Reactive Protein (CRP) (mg/L)") ///
    ytitle("Fibrinogen (mg/dL)") t1("Fibrinogen by CRP and Prior CVD")),   ///
	legend(label(5 "All subjects (lowess)") label(1 "Prior CVD") ///
	label(2 "Prior CVD (lowess)") label(3 "No Prior CVD") ///
	label(4 "No Prior CVD (lowess)"))

g icrp = crp
replace icrp=0.5 if crp==0
g logcrp= log(icrp) / log(2)
g logfib= log(fib)

twoway (scatter fib icrp if prevdis==1, jitter(2) col(blue) yscale(log) xscale(log)) ///
    (lowess fib icrp if prevdis==1, col(blue)) ///
    (scatter fib icrp if prevdis==0, jitter(1) col(pink) msymb(D)) ///
    (lowess fib icrp if prevdis==0, col(pink)) ///
	(lowess fib icrp, col(black) xtitle("C Reactive Protein (CRP) (mg/L)") ///
    ytitle("Fibrinogen (mg/dL)") t1("Fibrinogen by CRP and Prior CVD")),   ///
	legend(label(5 "All subjects (lowess)") label(1 "Prior CVD") ///
	label(2 "Prior CVD (lowess)") label(3 "No Prior CVD") ///
	label(4 "No Prior CVD (lowess)"))
	
recode crp 3/4=4 5/8=8 9/16=16 17/32=32 33/max=64, gen(ctgcrp)

tabulate ctgcrp prevdis, missing

tabstat crp, stat(n mean sd min q max) col(stat) by(prevdis)
bysort prevdis: tabstat fib, stat(n mean sd min q max) col(stat) by(ctgcrp) missing
tabstat fib, stat(n mean sd min q max) col(stat) by(ctgcrp) missing
tabstat fib if crp==., stat(n mean sd min q max) col(stat)

corr fib crp
spearman fib crp
corr logfib logcrp

ttest fib, by(prevdis)

regress fib prevdis

ttest fib, by(prevdis) unequal

regress fib prevdis, robust

regress fib crp, robust
regress fib logcrp, robust
regress logfib crp, robust
regress logfib crp, robust eform(GM)
regress logfib logcrp, robust
regress logfib logcrp, robust eform(GM)