Plotting Time Series data using ggplot2

September 30, 2010
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(This article was first published on Software for Exploratory Data Analysis and Statistical Modelling, and kindly contributed to R-bloggers)

There are various ways to plot data that is represented by a time series in R. The ggplot2 package has scales that can handle dates reasonably easily.

Fast Tube
Fast Tube by Casper

As an example consider a data set on the number of views of the you tube channel ramstatvid. A short snippet of the data is shown here:

> head(yt.views)
        Date Views
1 2010-05-17    13
2 2010-05-18    11
3 2010-05-19     4
4 2010-05-20     2
5 2010-05-21    23
6 2010-05-22    26

The ggplot function is used by specifying a data frame and the aes maps the Date to the x-axis and the number of Views to the y-axis.

ggplot(yt.views, aes(Date, Views)) + geom_line() +
  scale_x_date(format = "%b-%Y") + xlab("") + ylab("Daily Views")

The axis labels for the Date variable are created with the scale_x_date function where the format is specified as a Month/Year combination with the %b and %Y formatting strings. The graph that is produced is shown here:

Time Series Example

Time Series Plot Example with ggplot2 package

Other useful resources are provided on the Supplementary Material page.

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