Plot with R

Source: http://www.r-graph-gallery.com/

Why should you make plot in R?

You make plots by clicking!

But you DON'T like to click again!

Definitely you DON'T like to click again and again.! You want to reproduce it

Want more flexibilities with plot options

Easy integration with data analysis component

Components of a plot

Plot region

Y ax

is la

bel

sY

axis

tic

ks

X axis labelsX axis ticks

Margins

Outer Margin Areas

Plot title

1. High-level plotting functions: create a new plot on the graphics device, possibly with axes, labels, titles

plot(x,y, main = ‘My first plot’)

2. Low-level plotting functions: add more information to an existing plot: points, lines and labels

points(z, col=“dark red”)

3. Interactive graphics functions: interactively add information to, or extract information from, an existing plot

Additional: list of graphical parameters which can be manipulated to customizeyour plots

Basic group of plotting functions available in base graphics

plot(x,y, xlab = "Speed of car (miles/hr)", ylab = "Stopping distance (feet)",main = "My test plot using Car data")

Adding title, x axis label, y axis label

lab title (label) for axes

main overall title for the plot

Change font sizeTo increase the symbol size and font size and use character expansion (cex) argument

plot(x,y, xlab = "Speed of car (miles/hr)", ylab = "Stopping distance (feet)",main = "My test plot using Car data"),cex = 2, #change symbol sizecex.lab = 1.5, #you can use fractions!cex.main = 2)

Change symbolsUse pch argument to change symbols and use col to change the colors

plot(x,y, xlab = "Speed of car (miles/hr)", ylab = "Stopping distance (feet)",main = "My test plot using Car data"),cex = 2,cex.lab = 1.5,cex.main = 2,pch = 8, # change symbolcol = ‘blue’) # change color

Available pch Incomplete list of colors

Colors

colors() returns available color names in R

Continuous color ramp:rainbow(),heat.colors(),terrain.colors(),topo.colors(), cm.colors()

plot(x,y, xlab = "Speed of car (miles/hr)", ylab = "Stopping distance (feet)",main = "My test plot using Car data"),cex = 2,cex.lab = 1.5,cex.main = 2,pch = 16, # change symbolcol = rainbow(50) # change color

Add line

lty options for type = ‘l’

plot(x,y, xlab = “Test X", ylab = “Random Y",main = “My test plot"),cex = 2,cex.lab = 1.5,cex.main = 2,pch = 8,col = ‘red’)

lines(y, lty = 2, # line typelwd = 2) # line width

Xlabxlim

cex.labcol.lab

axes=FALSE

main

plot

legend

text

x-limits of the plot

x-axis label

Sam

e as

x-a

xis

Overview

color of axis labels

size of labels

do not plot axesGen

era

l axe

s se

ttin

gs

More control over axes; Create custom axis usingaxis(side, at=, labels=, pos=, lty=, col=, las=, tck=, ...)

mtext

legend(location, title, legend, ...)

text(location, "text in plot", pos, ...)

mtext(“text in margin", side, line=n, ...)

R-plots -> Graphical elements + Graphical parameters

Components of a plot

points, lines, text, polygons (filled regions)

control drawing ofgraphical elements

set using par()

Use of par() function

par() access and modify list of graphics parameters for current graphics device

examplepar(cex=‘2’, pch = ‘+’) default for all plots in current device

To save the par() settingoldpar <- par(font=2,font.axis=4)par(oldpar)

To reset par() close the current devicedev.off()

Multiple figures in same plot

Usingpar with number of rows (nr) and number of columns (nc)

> par(mfrow(nr,nc))

> par(mfrow=c(3,2))> par(mfcol=c(3,2))

Multiple figures in same plot

Using layout function

layout(matrix(c(1,2,3,4),2,2,byrow = TRUE), c(3,1), c(1,3), TRUE)

1 2

3 4

Save plots

Using following graphics driver

bmp()jpeg()tiff()png()pdf()…

Controls/arguments

filename: name of the output filewidth: width of deviceheight: height of deviceunit: unit of height and widthcompression: type of compression to be used bg: initial background colorres: resolution in ppi…

• plot.data.frame* • plot.density* • plot.factor* • plot.formula* • plot.function• plot.hclust* • plot.histogram* • plot.lm* • plot.prcomp* • plot.raster* • plot.ts

Available plot methods for R objects

For complete list use methods(plot)

Other packages for plotting in R

I’m stuck!!!Ask my friend?ask Google? You are not alone…Ask it ‘nicely and properly’!

“Help will always be given at ‘R-world’ to those who ask for it.”

http://stackoverflow.com/questions/7160565/how-to-create-a-time-scatterplot-with-r?rq=1