Matplot in R

Matplot in R is most concise way to superimpose the data series. Matplot  plots the columns of a matrix individually as a function of x.

Syntax for Matplot in R:

• x, y1, and y2 are vectors or column of a matrix or data frame

Example of matplot in R

# R matplot

X <- 1:10
Y=X^2
Z=X^2-2*X
matplot(X,cbind(Y,Z),pch=c(16,1),xlab="x",ylab="X^2 and X^2-2*X")

• X is vector from 1 to 10
• Y and Z are function of X
• The command matplot(x,cbind(y,Z)) will produce graph in which has points of the two data series, one is printed in black (col=1) and other is printed in red (col=2).
• xlab and ylab are x axis labels and y axis labels respectively

Note that matplot automatically sets ylim to include both data series.

So the output will be

Matplot in R with legend:

To identify the series, add a legend with the legend function, which specifies the x and y coordinates of the legend, its text, accompanying symbols or line types etc

Example of matplot in R with legend

# R matplot with legend

X <- 1:10
Y=X^2
Z=X^2-2*X
matplot(X,cbind(Y,Z),pch=c(16,1),xlab="x",ylab="X^2 and X^2-2*X")
legend(1,100,legend=c("y","Z"),pch=c(16,1)) 

use bty=”n” if you don’t want box, where bty stands for “box type”.

So the output will be