statistik Kurs ostfalia WirtschaftsInformatik
Code für Simulationen ################### 5 Wuerfel #########################
k <- 100000 s5 <- c() for (i in 1:k){ x <- sample(6,5,replace=T) s5 <- c(s5,sum(x)) }
length(subset(s5,s5<=6))/k
################# Wei�e Wuerfel #########################
k <- 10000 ball1 <- c() ball2 <- c() for (i in 1:k){ draw2 <- sample(c("w","w","b","b"),2,replace=F) ball1 <- c(ball1,draw2[1]) ball2 <- c(ball2,draw2[2]) }
b1gb2w <- subset(ball1,ball2=="w")
nob2w <- length(b1gb2w)
length(subset(b1gb2w,b1gb2w=="w"))/nob2w
################ Seltene Krankheit ########################
k <- 100000 person <- sample(c("g","k"),k,replace=T,prob=c(0.995,0.005)) testerg <- c() for (i in 1:k){ if (person[i]=="k"){ p.pos <- 0.99 }else{ p.pos <- 0.02 } test.i <- sample(c("p","n"),1,prob=c(p.pos,1-p.pos)) testerg <- c(testerg,test.i) }
ppostest <- subset(person,testerg=="p") ppostest.k <- subset(person,testerg=="p" & person=="k")
length(ppostest.k)/length(ppostest)
########## Monte-Carlo-Integration ##########################
k <- 100000 x <- runif(k,min=0,max=2) y <- runif(k,min=0,max=4)
pucx <- subset(x,x^2>y) 8*length(pucx)/k