d=read.table("http://www.biostat.umn.edu/~hanson/FundBiostat/bodytemp.txt",header=T,sep=",")
attach(d) # now you can refer to 'rate', 'temperature', and 'gender'
plot(rate,temperature,pch=gender)
plot(rate,temperature,pch=c(109,102)[gender])
fit.m=lm(temperature[gender==1]~rate[gender==1]) # only pick out men
summary(fit.m)
plot(fit.m)
fit.f=lm(temperature[gender==2]~rate[gender==2]) # women

d=read.table("http://www.biostat.umn.edu/~hanson/FundBiostat/calcium.txt",header=T)
attach(d)
diff=oxalate-flame
t.test(diff)

d=read.table("http://www.biostat.umn.edu/~hanson/FundBiostat/bearings.txt",header=T)
attach(d)
both=c(TypeI,TypeII)
group=c(rep('I',10),rep('II',10))
t.test(both~group)