ply_aes causes the aesthetics of a layer to be computed groupwise. ply_aes
implements the split-apply-combine strategy of data analysis in a graphical
framework. It first splits a layer's data frame into subgroups, then evaluates
the layers mappings separately within each group, and finally combines the
results into a single data frame which is used to build the plot for
rendering.
Usage
ply_aes(layer, .vars = NULL)
Arguments
layer
a ggplot2 layer or sp_layer object. This layer's aesthetics will
be computed groupwise, but the layer will remain the same in every other
respect.
.vars
variable names to group by (optional), stored as a character
string
Details
Users may specify which groupings to use through the .vars
argument. If this argument is left NULL, ply_aes will search for and use a
group aes, a glyphing or gridding criteria (in a sp_layer), a facetting
criteria, or any combination of these that it finds.