use pef,replace
lab var pef "Pef"
lab var day0 "Days since randomisation"
overlay pef day0, by(patient) c(l) s(.) sort saving(graph1)
overlay pef if patient<5028, by(patient) xlab(150,350,680) bin(8) ylab(0,1.1) saving(graph2)
overlay pef if patient<5028, by(patient) function(kdensity) xlab(150,350,680) ylab(0,0.02, 0.045) s(.) saving(graph3)