R-ko

ul.1A
funkcia <- function(n){
for(i in 1:n){
if(i %% 2 == 0){ print(i^2)}
else if((i %% 3 == 0) && (i %% 5 == 0)) {print(i^3)}
else {print(i)}
}
}
funkcia(7)
---------------------------------------------------------------
ul.2A
getwd()
dir.create("Zapocet1")
setwd("C:/Users/Sára/Documents/Zapocet1")
dir.create("data")
fileURL = "odkaz
download.file(fileURL, destfile = "./SalesJan2009.csv")
data = read.csv("./SalesJan2009.csv")
head(data, n = 10)
tail(data, n = 15)
data[1:5,2:3]
--------------------------------------------------------------
ul.3A
set.seed(10)
install.packages("data.table")
library(data.table)
tabulka = data.table(A=rnorm(10),B=1:10,C=10:1,D=rep(factor(c("a","b")),each = 5))
tabulka[[1]][2] = NA
tabulka[[1]][4] = NA
tabulka
tabulka[(which(tabulka$A != is.na(A))),mean(A)]
tabulka[,e:=B^2]
tabulka
tabulka[,f:=sum(B),by=D]
sort(tabulka$C)
tabulka[order(tabulka$C),]
--------------------------------------------------------------
ul.4A
library(datasets)
attach(infert)
boxplot(age ~ education, infert, col = "red", xlab = "Age", ylab = "Education", main = "infert")
abline(h = 30, lwd = 3, lty = 2, col = "blue")
library(lattice)
xyplot(stratum ~ age | education, data = infert)