#################### set working directory ################################## setwd("") dir() ###################### use as calculator ############################ 4+12 7-3 5*6 4/2 2^8 5+2^8 (5+2)^8 ############################## functions and help ############################## ?log ?mean ############################# assignment operator ############################## x<-8 x<-8L x<-"hello world!" x<-TRUE x<-8+2i x ############################# data types and containers ################### class(x) as.numeric(x) ## conversion y<-as.logical(x) y ## vectors ?vector() Avektor<-c(5,6,2,4,8) str(Avektor) class(Avektor) is.vector(Avektor) Bvektor<-c(1:20) Bvektor<-c(as.numeric(1:20)) class(Bvektor) str(Bvektor) Avektor Bvektor Cvektor<-c("hi","hello","seeya") Dvektor<-c(Avektor,Bvektor,Cvektor) Dvektor class(Dvektor) str(Dvektor) Avektor[1] # simple selector Avektor[2:5] # sequence selector Avektor[c(2,4)] # vector selector Avektor[Avektor>3] #logical selector ##lists mylist<-list(2,TRUE,"Peter",84.321,FALSE) mylist class(mylist) str(mylist) summary(mylist) ## factors ?factor jegyek<-c(5,2,1,4,3,1,2,5) # create a vector! grades<-factor(jegyek) # convert it to factor as.factor(jegyek) # this is also a valid conversion class(jegyek) class(grades) table(grades) nemek<-(factor(c("Male","Female","Female","Male"))) # vector creation and conversion in one step nemek str(nemek) table(nemek) class(nemek) ## matrices ?matrix() M<-matrix(1:50,nrow=5,ncol=10) dim(M) vektor1<-c(1:10) vektor2<-c(11:20) mat<-cbind(vektor1,vektor2) mat rbind(vektor1,vektor2) class(mat) ## data frames (file import) ?data.frame() ############################### data import #####################################x c<-read.table("leveltetu.txt",header=TRUE) c str(c) d<-read.csv("leveltetu.csv") summary(d) str(d) d$x ## attach to memory attach(d) x cirok<-(read.csv("cirok.csv")) cirok str(minta) str(cirok$minta) attach(cirok) str(minta) summary(minta) kerdoiv<-(read.csv("kerdoiv.csv")) str(kerdoiv) kerdoiv attach(kerdoiv) ######################## basic statistical functions ################################### summary(x) is.data.frame(d) is.vector(x) dim(d) mean(d$x) mean(x) median(x) sd(x) x table(x) ######################## plots ###################################### ?hist hist(x) hist(minta) hist(ppm) hist(mmol.g,col="blue") Nem barplot(table(Nem)) barplot(table(Kor)) ?png png("histogram.png",width = 480, height = 480, units = "px") hist(x,col="indianred") dev.off() ############ deleting tables from the memory ###################### detach(d) detach(cirok) detach(kerdoiv)