Graphics in R

• X<-c(1:25)

• Y<-X^2

Plot(X,Y)#more examples later

plot(X,Y,type="l") # more examples later

plot(X,Y,type="b")

plot(X,Y,type="c")

plot(X,Y,type="o")

plot(X,Y,type="S")

0 100 200 300 400 500

05

00

00

10

00

00

15

00

00

20

00

00

X

Y

Main and labels

• plot(X,Y,main="Fuelconsumption for cars", xlab="weight of car",ylab="cl per mile",cex.lab=1.5, sub ="source: Källa",cex.main=2)

• Xlab creates label for X

• Ylab creates label for Y• Sub creates subtitle• cex.lab decides size of text on labels• cex.main decides size of text on header

5 10 15 20 25

01

00

20

03

00

40

05

00

60

0

Fuelconsumption for cars

source: Källaweight of car

cl p

er m

ile

• plot(X,Y)

• It is problematic to use function ”title” for writing labels because it writes over original labels

• title(main="Fuelconsumption for cars", xlab="weight of car",ylab="cl per mile”)

• par(mfrow=c(2,2)) #Multiple graphs in one picture. Choose your own dimensions i with

• # To illustrate different points is given by pch

• X<-c(1,2,3,4,5)

• Y<-X^2

• plot(X,Y, pch=1, main=" turned squares")

• plot(X,Y, pch=2, main ="triangel")

• plot(X,Y, pch=3,main="plus")

• plot(X,Y, pch=4,main="X")

plot symbols : points (... pch = *, cex = 3 )

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

**

.

oo

OO

00

++

--

||

%%

##

Get your own symbols

• plot(X,Y, pch="*",main=”starplot")

• Or choose your own string

• z<-c("H", "Å", "K", "A", "N")

• plot(X,Y, pch=z,main="Nameplot")

Text instead of points

• data<-read.table("Rstudy.txt",header=TRUE)

• attach(data)

• plot(beer,wine,type="n")

• text(beer,wine,country)

Regression

• library(foreign)• lnu91<-read.dta("lnu91.dta")• gender<-lnu91$y10• wage<-lnu91$y472• age<-lnu91$y11• lnu<-data.frame(wage,age,gender)• lnu<-na.omit(lnu)• rm(lnu91)• rm(age,wage,gender)• lnu<-subset(lnu, age<67 & wage<300&wage>0)• attach(lnu)• plot(age,log(wage))• abline (lm(log(wage) ~ age )) #regressionslinje

Show different subgroups

plot(age,wage,col=as.numeric(gender))

• Col sets colour.

• R has over 650 different colours. Get a list with colors()

• plot(age,wage,col=as.numeric(gender),pch=as.numeric(gender))

• Pch sets different characters

• Use replace to get the ”right” number

Saving graphs

• In pdf• pdf("myfile.pdf")• plot(X,Y)……………

• dev.off()

• In postscript• postscript("myfile.eps“, horizontal=FALSE) (A4)• plot(x,y) ……………• dev.off()

• In JPEG• jpeg("myfile.jpeg")• plot(X,Y)……• dev.off()

• Similar is available for png and bmp

Drawing functions

• curve(atan(x),-25,25)

• z<-seq(-25,0,0.01)

• a <-seq(0,25,0.01)

• z2<-c(rep(-1.57,length(z)))

• a2<-c(rep(1.57,length(a)))

• lines(a,a2,lty=2)

• lines(z,z2,lty=2)

• title(main="arctan")

Plotting normaldistribution

• For educationalpurposes (Picture on next slide)

• nx<-seq(-3,3,0.01)

• N<-dnorm(nx)

• plot(nx,N,type="l")

• polygon(c(nx[nx>=1.96],1.96),c(N[nx>=1.96],N[nx==3]),col="pink")

• arrows(2.6,0.1,2.5,0.01)

• text(2.65, .12,"2.5 %")

Histogram

• hist(wage)

• hist(wage,breaks=40)

• hist(wage,breaks=40,freq=FALSE)

• hist(wage,breaks=seq(0,300,20))

• It is possible to cheat R with!!!

• hist(wage,breaks=c(0,25,50,75,100,125,500),freq=TRUE)

• With normal distribution curve

• hist(wage,breaks=40, prob=TRUE)

• x <- seq(0,400,1)

• lines(x,dnorm(x,mean(wage),sd(wage)))

Normal distributed?

• qqnorm(wage)

• qqline(wage)

• qqnorm(log(wage))

• qqline(log(wage))

Barchart• occu<-

c(rep("Steelworker",320),rep("Chef",250),rep("Gardner",200),rep("Constructionworker",130))

• barplot(occu) #doesn’t work• occ.table <- table(occu)• farger<-c("gold1", "gold2", "gold3", "gold4 ") #Chooses a string with

colournames)• barplot(occ.table,col=farger)• barplot(occ.table,col=farger)• barplot(occ.table,col=farger,horiz=TRUE,main="occupations",xlab="

Frequency")• Source for further barcharts issuses• http://ww2.coastal.edu/kingw/psyc480/html/barplot_tips.html

Barcharts continuing

• Gender<-rep(c("man","man","woman","woman","woman","man","man","man","woman","man"),time=90) #creates Gender variabel

• Occ.table2<-table(Gender,occu)

• Occ.table2<-table(Gender,occu) #legend gives ”box”

• barplot(Occ.table2,legend=T,ylim=c(0,400))

• # Bedside gives pairwise, ylim sets range of y

• barplot(Occ.table2,legend=T,ylim=c(0,250),beside=T)

Piechart

• seq(0.4,1.0,length=4)

• 0.4 0.6 0.8 1.0

• pie(occ.table, col=gray(seq(0.4,1.0,length = 4)))

• Radius decides how big radius is to be

• Too change background colour:

• par(bg="pink") # sets to pink until changed

• pie(occ.table, col=gray(seq(0.4,1.0,length = 4)))

Different sizes of the symbols

• Different sizes of the symbols is given by

• Q<-c(7,3,4,5,12) #gives different sizes for the coordinates

• symbols(X,Y,squares = Q)

• # Färglägger

• W<-c(2,3,6,3,6)

• symbols(X,Y,squares = Q,fg=W)

• symbols(X,Y,squares = Q,bg=W)

• symbols(X,Y,squares = Q,bg=W,fg=W)

• Country<-c ("Sweden", "Iceland", "Denmark", "Finland", "Norway")

• text(X,Y,Country)

Different kinds of lines

• par(mfrow=c(2,1))

• plot(X,Y, type=“l”,lty=0, main= “blank line”)

• plot(X,Y, type=“l”,lty=1, main= “solid line”)

• plot(X,Y, type=”l”,lty=2, main= “dashed line”)

• plot(X,Y, type=”l”,lty=3, main= “dotted line”)

• plot(X,Y, type=”l”,lty=4, main= “dotdash line”)

• plot(X,Y, type=”l”,lty=5, main= “longdash line”)

• plot(X,Y, type=”l”,lty=6, main= “twodash line”)