This document contains slides from a data visualization course in R. It discusses how to modify the title, axis labels, and range of plots created in R. Specifically, it shows how to add these elements either by including arguments in the plot() function or by using the title() function. The title(), xlab, ylab, xlim, and ylim arguments can be used in plot() to customize the title, axis labels, and ranges. Alternatively, the title() function can be used after plotting but may overwrite default axis labels, so the ann argument should be set to FALSE in plot().

1. www.r-squared.in/git-hub
dataCrunch Data Visualization With R
Learn To Modify Title, Axis Labels & Range

2. dataCrunchCourse Material
Slide 2
All the material related to this course are available at our Website
Slides can be viewed at SlideShare
Scripts can be downloaded from GitHub
Videos can be viewed on our Youtube Channel

3. dataCrunch
Title, Axis Labels & Range
Slide 3

4. dataCrunchTitle & Labels
Slide 4
In this section, we will learn to enhance the plot by adding/modifying the following features:
● Title
● Subtitle
● Axis Labels
● Axis Range

5. dataCrunchIntroduction
Slide 5
In the previous section, we created plots which did not have any title or labels. A new user of a plot
should know what the X and Y axis represent as well as the primary information being communicated
by the plot. The title, axis labels and range play an important role in making the plot holistic.
There are two ways of adding the above mentioned elements to a plot:
● Use the relevant arguments within the plot() function.
● Use the title() function.
We will explore both the methods one by one and you can choose the method that you find most
convenient. Let us begin by adding the features using the plot() function.

6. dataCrunchSyntax
Slide 6
Feature Argument Value Example
Title main String “Scatter Plot”
Subtitle sub String “Displacement vs Miles Per Gallon”
X Axis Label xlab String “Displacement”
Y Axis Label ylab String “Miles Per Gallon”
X Axis Range xlim Numeric Vector c(0, 500)
Y Axis Range ylim Numeric Vector c(0, 50)

7. dataCrunchTitle
Slide 7
# create a basic plot and add a title
plot(mtcars$disp, mtcars$mpg,
main = “Displacement vs Miles Per Gallon”)
Description
Use the main argument in the plot()
function to add a title to the plot. The title
must be enclosed in double quotes as it is a
string.
Code

8. dataCrunchSubtitle
Slide 8
# create a basic plot and add a subtitle
plot(mtcars$disp, mtcars$mpg,
sub = “Displacement vs Miles Per Gallon”)
Description
Use the sub argument in the plot()
function to add a subtitle to the plot. The
subtitle must be enclosed in double quotes
as it is a string.
Code

9. dataCrunchAxis Labels
Slide 9
# create a basic plot and add axis labels
plot(mtcars$disp, mtcars$mpg,
xlab = "Displacement",
ylab = "Miles Per Gallon")
Description
In all plots created till now, the axis labels
appear as mtcars$disp and mtcars$mpg.
It is not the most elegant way of labeling the
axis and it would make more sense to use
appropriate names. Use the xlab and ylab
arguments in the plot() function to add the
X and Y axis labels.
Code

10. dataCrunchAxis Range
Slide 10
# create a basic plot and modify axis range
plot(mtcars$disp, mtcars$mpg,
xlim = c(0, 600),
ylim = c(0, 50))
Description
The range of the axis can be modified using
the xlim and ylim arguments in the
plot() function. The lower and upper limit
for both the axis must be mentioned in a
numeric vector.
Code

11. dataCrunchSo far...
Slide 11
# create a plot with title, subtitle, axis
labels and range
plot(mtcars$disp, mtcars$mpg,
main = "Displacement vs Miles Per Gallon",
sub = "Scatter Plot",
xlab = "Displacement",
ylab = "Miles Per Gallon",
xlim = c(0, 600), ylim = c(0, 50))
Description
Let us create a plot that has all the features
that we have learnt so far:
Code

12. dataCrunchtitle() Function
Slide 12
# create a basic plot
plot(mtcars$disp, mtcars$mpg)
# add title and label using title() function
title(main = "Displacement vs Miles Per Gallon",
sub = "Scatter Plot",
xlab = "Displacement",
ylab = "Miles Per Gallon")
Description
We will add/modify the same set of features but
using the title() function instead of the
arguments in the plot() function but we will
continue to use the plot() function for creating the
basic plot.
Code
Oops.. We have a problem. If you have observed
carefully, the title() function has overwritten the
default axis labels created by the plot() function.

13. dataCrunchtitle() Function
Slide 13
# create a basic plot
plot(mtcars$disp, mtcars$mpg, ann = FALSE)
# add title and label using title() function
title(main = "Displacement vs Miles Per Gallon",
sub = "Scatter Plot",
xlab = "Displacement",
ylab = "Miles Per Gallon")
Description
Use the ann argument in the plot() function and
set it to FALSE to ensure that the plot() function
does not add the default labels.
Code
Note: The range of the axis cannot be modified
using the title() function.

14. dataCrunch
Slide 14
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