#Datensatz laden
IrishExams2 <- read.table("/Users/antonyunwin/Documents/StatsI2009-f/IrishExams2.txt",header=T,sep="\t",quote="")

#Daten beschreiben (Statistiken)
summary(IrishExams2)
mean(IrishExams2[,6:14])
mean(IrishExams2[,6:14],na.rm=TRUE)
sd(IrishExams2[,6:14],na.rm=TRUE)
var(IrishExams2[,6:14],na.rm=TRUE)
var(IrishExams2[,6:14],use="pair")

#Daten beschreiben (Graphiken)
JavaGD()
par(mfrow=c(2,1))
hist(IrishExams2$MATHS)
hist(IrishExams2$IRISH)
hist(IrishExams2$MATHS,xlim=c(0,100))
hist(IrishExams2$IRISH,xlim=c(0,100))
JavaGD()
boxplot(IrishExams2$MATHS,IrishExams2$IRISH)

#Testen
var(IrishExams2$MATHS,na.rm=TRUE)
var(IrishExams2$IRISH,na.rm=TRUE)

t.test(IrishExams2$MATHS,IrishExams2$IRISH)
t.test(IrishExams2$MATHS,IrishExams2$IRISH,var.equal=TRUE)
t.test(IrishExams2$MATHS,IrishExams2$IRISH,paired=TRUE)

hist(IrishExams2$MATHS-IrishExams2$IRISH)

#Was gibt es im t.test?
atest<-t.test(IrishExams2$MATHS,IrishExams2$IRISH,var.equal=TRUE)
str(atest)
atest$conf.int

t.test(IrishExams2$MATHS,IrishExams2$IRISH,conf.level=0.99)
t.test(IrishExams2$MATHS,IrishExams2$IRISH,var.equal=TRUE,,conf.level=0.99)
t.test(IrishExams2$MATHS,IrishExams2$IRISH,paired=TRUE,conf.level=0.99)