geom_line and related. As almost all edge
representations are lines of some sort, edge_width will be used much more
often than edge_size. It is not necessary to spell out that it is an edge
scale as the geom knows if it is drawing an edge. Just write width and
not edge_width in the call to geoms.
scale_edge_width_continuous(..., range = c(1, 6))
scale_edge_width(..., range = c(1, 6))
scale_edge_width_discrete(..., range = c(2, 6))
scale_edge_width_manual(..., values)
scale_edge_width_identity(..., guide = "none")continuous_scale
to control name, limits, breaks, labels and so forth.na.value.Scale
scale_edge_alpha,
scale_edge_colour,
scale_edge_fill,
scale_edge_linetype,
scale_edge_shape,
scale_edge_size,
scale_label_size