labelr_polygon_list: Calculate polygon label positions using Pole of...

In jmw86069/venndir: Directional Venn diagrams

Calculate polygon label positions using Pole of Inaccessibility

Description

Calculate polygon label positions using Pole of Inaccessibility, otherwise known as the Visual Center.

Usage

labelr_polygon_list(polygon_list, add_labels = FALSE, ...)

Arguments

polygon_list	list containing elements "x" and "y" each with numeric vectors, or list of numeric vectors.
add_labels	logical indicating whether to plot the labels using text()
...	additional arguments are passed to text() when add_labels=TRUE

Details

This function is a wrapper for polylabelr::poi() except that it is applied to a list of polygons individually.

When any one polygon is composed of two smaller polygon components, as encoded with a nested list of coordinates, first the polygons are combined using union_polygon_list(). If the result is a single polygon, that is used to define the label position. If the result is multiple separate polygon components, the largest polygon component is used to find the label.

See Also

Other venndir polygons: bbox_polygon_list(), eulerr_to_polygon_list(), get_largest_polygon_list(), get_venn_polygon_shapes(), intersect_polygon_list(), minus_polygon_list(), nudge_polygon_coords(), nudge_polygon_list(), plot_polygon_list(), polygon_areas(), polygon_circles(), polygon_ellipses(), polygon_list_labelr(), polygon_list_to_xy_list(), rescale_polygon_list(), simple_ellipse(), union_polygon_list(), xy_list_to_polygon_list()

Examples

counts <- c(A=1, B=2, `A&B`=3, C=5, `B&C`=2, `A&C`=2, `A&B&C`=1)
x <- eulerr::euler(counts)
polygon_list <- eulerr_to_polygon_list(x)

# default is to label each polygon in its center
plot_polygon_list(polygon_list,
   col=colorjam::rainbowJam(length(polygon_list), alpha=0.5))
labelr_polygon_list(polygon_list, add_labels=TRUE)

# create unique polygons for each label
A_only <- minus_polygon_list(polygon_list, new_name="A_only");
B_only <- minus_polygon_list(polygon_list[c(2,1,3)], new_name="B_only");
C_only <- minus_polygon_list(polygon_list[c(3,1,2)], new_name="C_only");

plot_polygon_list(polygon_list,
   col=colorjam::rainbowJam(length(polygon_list), alpha=0.5))
ABC_only <- c(A_only, B_only, C_only);
polygon_list_labelr(ABC_only, add_labels=TRUE)

# label ABC intersection
ABC_int <- intersect_polygon_list(polygon_list[c(1,2,3)], new_name="ABC");
plot_polygon_list(ABC_int, add=TRUE, col="gold")
polygon_list_labelr(ABC_int, add_labels=TRUE)

# label AB intersection
AB_only <- minus_polygon_list(
   c(intersect_polygon_list(polygon_list[c(1,2)], new_name="BC_only"),
      polygon_list[3]))
plot_polygon_list(AB_only, add=TRUE, col="darkviolet")
polygon_list_labelr(AB_only, add_labels=TRUE, col="white")

# label BC intersection
BC_only <- minus_polygon_list(
   c(intersect_polygon_list(polygon_list[c(2,3)], new_name="BC_only"),
      polygon_list[1]))
plot_polygon_list(BC_only, add=TRUE, col="skyblue")
polygon_list_labelr(BC_only, add_labels=TRUE)

jmw86069/venndir documentation built on June 15, 2024, 1:52 p.m.