A base version of link_draw()
, optimized for performance. This function
serves as the foundation for building other link_*
functions that manage
the drawing of links between pairs of observations.
Arguments
- .draw
A function used to draw the links. The function must return a
grob()
object. If the function does not return a validgrob
, no drawing will occur. The input data for the function should be a list, where each item is a data frame containing the coordinates of the pair of observations.- ...
<dyn-dots> A list of formulas, where each side of the formula should be an
integer
orcharacter
index of the original data, or arange_link()
object defining the linked observations. UseNULL
to indicate no link on that side. You can also combine these by wrapping them into a singlelist()
. If only the left-hand side of the formula exists, you can input it directly. For integer indices, wrap them withI()
to use the ordering from the layout. You can also usewaiver()
to inherit values from the other group.