This function returns another function that can extract nodes from a
ggraph_layout object. As a ggraph_layout object is essentially a data.frame
of nodes it might seem useless to provide this function, but since the node
data is not necessarily available until after the ggraph() call it
can be beneficial to be able to add information to the node data on a
per-layer basis. Unlike get_edges() the use of get_nodes is not
mandatory and is only required if additional data should be added to selected
node layers.
get_nodes(...)A data.frame with the node data as well of any additional data
supplied through ...
Additional data that should be cbind'ed together with the node data.
Other extractors:
get_con(),
get_edges()