a<-4
b<-6

a+2*b



# így lehet kommentelni, c<-4

?getwd
getwd()

# A (Session/Working directory) helyett így is be lehet állítani a working directory-t


setwd("")


a<-1:5

a

mode(a)


b<-c(  1,2,2,4,5,1  )

b

mode(b)

length(b)


b[3]

b[c(3,6)]

b[2:4]

10



ourlist<-list( 1,"hello",TRUE )

ourlist[[2]]
ourlist[2]


if(ourlist[3]){
  print("success")  
}

if(ourlist[[3]]){
  print("success")  
}

ourlist[3]

ourlist[[3]]



?read.table

cholesterol<-read.table("cholestr.txt",header=TRUE)

View(cholesterol)

cholesterol[[2]]

cholesterol$Day4

cholesterol[3,2]

cholesterol[3,]

cholesterol[,2]

?t.test
t.test(cholesterol$Day2,mu=260)

weights<-c(25.1,24.7,24.9,25.2,24.8,24.4,24.9,24.8,24.7)

t.test(weights,mu=25)

t.test(weights,mu=25,alternative="less")

load("choleverybody.RData")

View(choleverybody)

subset(choleverybody,group==1)
day2p<-subset(choleverybody,group==1)$cholest2
day14p<-subset(choleverybody,group==1)$cholest14

t.test(day2p,day14p,paired=TRUE)

h<-subset(choleverybody,group==2)$cholest2

?t.test
t.test(h,day14p,paired=FALSE)