A default plot

Here some random numbers were generated to make a plot. First let us see what we get as default.

set.seed(111)
x=round(runif(50, 0, 30))
set.seed(121)
y=10+(0.5*x+rnorm(50,0,10))^2
plot(y~x, main="Default Plot")

Now waht we see here is the default plot generated by R. The symbols are by default chosen as circles, color is by default black, and the axes ranges and labels are chosen by default. We see the axis tick marks are all parallel to the respective axes. Often we want to make it custimized like,

• Make the symbols other than circles
• Want different axis range
• Want different color
• Want all tick labels hozizontal
• Want to reduce the sapce between axis and label… and so on.

Let us try to do these customizations. We will only work on the base R graphics.

Change Symbols and colors

This is very simple task and done by passingpch and col arguments.

plot(y~x, pch=16, main="Solid Circle")

plot(y~x, pch=4, main="X Mark")

plot(y~x, pch=5, main="Diamond")

plot(y~x, pch=16, col="red", main="Solid Red Circle")

Explore other options

plot(y~x, pch=16, cex=2, main="Change Symbol Size")

plot(y~x, xaxt="none", main="Turn off x-axis")

plot(y~x, yaxt="none", main="Turn off y-axis")

plot(y~x, xaxt="none", main="Redefined/Customized x-axis")
axis(1, seq(0,30,10))

plot(y~x, yaxt="none", main="Redefined/Customized y-axis")
axis(2, seq(0,700,50))

plot(y~x, yaxt="none", main="Rotate y-axis tick labels")
axis(2, seq(0,700,100),las=2)

plot(y~x, xaxt="none", main="Bold x-axis tick labels")
axis(1, seq(0,30,5), font=2)

plot(y~x, yaxt="none", main="Bold y-axis tick labels")
axis(2, seq(0,700,100),las=2, font=2)

plot(y~x, yaxt="none", ylim=c(0,1000), main="Extended Y limit")
axis(2, seq(0,1000,100),las=2, font=2)

plot(y~x, yaxt="none", xlim=c(0,40), main="Extended X limit")
axis(2, seq(0,700,100),las=2, font=2)

plot(y~x, xlab="New X label", ylab="New Y label",main="Change axis lables")

plot(y~x)
mtext(side=3, line=0.2, "Reduced Space here")

plot(y~x)
mtext(side=3, line=0.2, "Reduced Space here, bold",font=2)

plot(y~x)
mtext(side=3, "Reduced font size, bold",font=2,cex=0.5)

plot(y~x)
mtext(side=3, "Bigger font size, bold",font=2,cex=2)

plot(y~x,xaxt="none")
axis(1, seq(0,30,1))
mtext(side=3, "X Axis tick labels are messy",font=2)

plot(y~x,xaxt="none")
axis(1, seq(0,30,1),las=2)
mtext(side=3, "Rotate X-axis tick labels",font=2)

plot(y~x,xaxt="none")
axis(1, seq(0,30,1),las=2, cex.axis=0.8, font=2)
mtext(side=3, "Reduce X-axis tick labels font size",font=2)

plot(y~x,xaxt="none")
axis(1, seq(0,30,1),las=2, cex.axis=0.8, font=2,col.axis="red")
mtext(side=3, "Change axis color",font=2)

par(mar=c(7,6,5,1)) ## set the margin
## starting from bottom, goes clockwise
plot(y~x, xaxt="none", yaxt="none", xlab="",ylab="",
     col="deeppink",cex=1.5,pch=16)
axis(1, seq(0,30, 1),las=2, font=2,cex.axis=0.8)
axis(2, seq(0,700,100),las=2, font=2)
## draw some lines
abline(h=seq(0,700,100), v=seq(0,30, 1), lty=3, col="gray")
mtext(side=1, line=2, "X-axis label, bold, bigger", col="blue", font=2,cex=1.2)
mtext(side=2, line=3, "Y-axis label, bold, bigger", col="orange", font=2, cex=1.2)
mtext(side=3, line=0.5, "Main title, italic", col="forestgreen", font=3, cex=2)
text(x=5, y=600, "Add some text, reduced font",col="gold4", font=2, cex=0.8)