These functions provide summarised information about built ggplot objects.
summarise_layout(p) summarise_coord(p) summarise_layers(p)
| p | A ggplot_built object. |
|---|
There are three types of summary that can be obtained: A summary of the plot layout, a summary of the plot coord, and a summary of plot layers.
The function summarise_layout() returns a table that provides information about
the plot panel(s) in the built plot. The table has the following columns:
panelA factor indicating the individual plot panels.
rowRow number in the grid of panels.
colColumn number in the grid of panels.
varsA list of lists. For each panel, the respective list provides the variables and their values that specify the panel.
xmin, xmaxThe minimum and maximum values of the variable mapped to the x aesthetic, in transformed coordinates.
ymin, ymaxThe minimum and maximum values of the variable mapped to the y aesthetic, in transformed coordinates.
xscaleThe scale object applied to the x aesthetic.
yscaleThe scale object applied to the y aesthetic.
Importantly, the values for xmin, xmax, ymin, ymax, xscale, and yscale
are determined by the variables that are mapped to x and y in the aes() call.
So even if a coord changes how x and y are shown in the final plot (as is the case
for coord_flip() or coord_polar()), these changes have no effect on the results
returned by summarise_plot().
The function summarise_coord() returns information about the log base for
coordinates that are log-transformed in coord_trans(), and it also indicates
whether the coord has flipped the x and y axes.
The function summarise_layers() returns a table with a single column, mapping, which
contains information about aesthetic mapping for each layer.
p <- ggplot(mpg, aes(displ, hwy)) + geom_point() + facet_wrap(~class) b <- ggplot_build(p) summarise_layout(b)#> # A tibble: 7 x 10 #> panel row col vars xmin xmax ymin ymax xscale yscale #> <fct> <int> <int> <list> <dbl> <dbl> <dbl> <dbl> <list> <list> #> 1 1 1 1 <named list [1… 1.33 7.27 10.4 45.6 <SclCntnP> <SclCntn… #> 2 2 1 2 <named list [1… 1.33 7.27 10.4 45.6 <SclCntnP> <SclCntn… #> 3 3 1 3 <named list [1… 1.33 7.27 10.4 45.6 <SclCntnP> <SclCntn… #> 4 4 2 1 <named list [1… 1.33 7.27 10.4 45.6 <SclCntnP> <SclCntn… #> 5 5 2 2 <named list [1… 1.33 7.27 10.4 45.6 <SclCntnP> <SclCntn… #> 6 6 2 3 <named list [1… 1.33 7.27 10.4 45.6 <SclCntnP> <SclCntn… #> 7 7 3 1 <named list [1… 1.33 7.27 10.4 45.6 <SclCntnP> <SclCntn…summarise_coord(b)#> $xlog #> [1] NA #> #> $ylog #> [1] NA #> #> $flip #> [1] FALSE #>summarise_layers(b)#> # A tibble: 1 x 1 #> mapping #> <list> #> 1 <named list [2]>