Database Reference
In-Depth Information
Figure 3.7 Anscombe's quartet visualized as scatterplots
The R code for generating Figure 3.7 is shown next. It requires the R package
ggplot2 [11], which can be installed simply by running the command
install.packages("ggplot2") . The anscombe dataset for the plot is
included in the standard R distribution. Enter data() for a list of datasets
included in the R base distribution. Enter data( DatasetName ) to make a dataset
available in the current workspace.
In the code that follows, variable levels is created using the gl() function,
which generates factors of four levels (1, 2, 3, and 4), each repeating 11 times.
Variable mydata is created using the with( data , expression ) function,
which evaluates an expression in an environment constructed from data . In
this example, the data is the anscombe dataset, which includes eight attributes:
x1 , x2 , x3 , x4 , y1 , y2 , y3 , and y4 . The expression part in the code creates a
data frame from the anscombe dataset, and it only includes three attributes: x , y ,
and the group each data point belongs to ( mygroup ).
install.packages("ggplot2") # not required if package has
been installed
data(anscombe) # load the anscombe dataset into the current
workspace
anscombe
x1 x2 x3 x4 y1 y2 y3 y4
Search WWH ::




Custom Search