R Plot Graph

• Function plot() is the main tool for 2D plotting in R.
• If we have two vectors x, y of equal length, function plot(x,y) allows us to get the graph of y(x) dependence.
• The function plot(x,y) takes parameters for specifying points in the diagram.
  1. Parameter 1 specifies points on the x-axis.
  2. Parameter 2 specifies points on the y-axis.

If only one variable is given, we will get a graph for which set vector provide the ordinate values and the points ordinal numbers are abscissas.

Syntax of the Plot Function in R

The generic syntax for a plot in Rstudio is:

Plot(x,y,…)

And its complete syntax is:

plot(x, y, type, main, sub,  xlab, ylab)

Some arguments of the plot() function:

Following arguments in details.

S.No	Parameter	Description
1.	v	It is a vector which contains the numeric values. x is specifies points on the x-axis. y is specifies points on the y-axis.
2.	type	change the plot type. It accepts the following strings and has the given effect.”p” – points “l” – lines “b” – both points and lines “c” – empty points joined by lines “o” – overplotted points and lines “s” and “S” – stair steps “h” – histogram-like vertical lines “n” – does not produce any points or lines
3.	xlab	It is the label for the x-axis.
4.	ylab	It is the label for the y-axis.
5.	main	It is the title of the chart.
6.	col	It is used to give the color for both the points and lines
7	pch	pch is used to change the point shape format.
8	cex	Use cex=number to change the size of the points
9	Legend()	Legend takes as input the coordinates, text and the symbols to be interpreted.
10	Ity	lty is the text sequence of four numbers from 1 to 9, for example: lty = “4241”.

Example : Single Point

Input:To draw single point using plot function

plot(2, 3)

Result:

Example : Multiple Point

Input: To draw multiple point using plot function

plot(c(1, 2, 3, 4, 5), c(3, 7, 8, 9, 12))

Output:

Example : Sequences of Points

Input: To draw a sequence of points using plot function

plot(1:10)

Output:

Example : Plot Labels and Colors

Input: To draw Plot Labels and Colors using main, xlab, ylab, col parameter

plot(1:10, main=”My Graph”, xlab=”The x-axis”, ylab=”The y axis”, col=”blue”)

Output:

Example : Size and Point Shape

Input: To draw size and point shape using “cex” and “pch” parameter

plot(1:10, main=”My Graph”, xlab=”The x-axis”, ylab=”The y axis”, pch=13, cex = 3)

Output:

The values of the pch parameter ranges from 0 to 25, which means that we can choose up to 26 different types of point shapes: