# Practicals 7
people<-read.csv2("01_data.csv", sep=";")
people<-people[,1:3]
summary(people)

means<-aggregate(people$height, list(people$eye.color, 
            people$sex), mean)


library(sciplot)

ses<-aggregate(people$height, list(people$eye.color,
      people$sex), se)
dfs<-aggregate(people$height, list(people$eye.color,
      people$sex), length)
dfs<-dfs$x-1

sds<-aggregate(people$height, list(people$eye.color,
        people$sex), sd)
ns<-aggregate(people$height, list(people$eye.color,
        people$sex), length)
ses<-sds$x/sqrt(ns$x)

CI.low<-means$x+ses$x*qt(0.025, dfs)
CI.high<-means$x+ses$x*qt(0.025, dfs, 
                          lower.tail=F)

x.coord<-barplot(means$x, ylim=c(150, 200))
arrows(x0=x.coord, y0=CI.low, y1=CI.high,
       code=3, angle=90, length=0.03)

qt(0.025, 1000)

### task 2

ran<-read.delim2("clipboard")
summary(ran)

t.test(AL~sp, data=ran)

t.test(AL~sp, data=ran, var.equal=T)

boxplot(AL~sp, data=ran)

### Task 3
fert<-read.delim2("clipboard")
summary(fert)
t.test(fert$F, fert$NF, paired=T)
t.test(fert$F, fert$NF, paired=F)

boxplot(fert$F-fert$NF)