compute_polygon_area: Compute polygon area

In mathiasisaksen/artKIT: Useful functions for creating visual/generative art

Description

This function takes in a data frame containing one or more polygons, and computes the (signed) area of each polygon.

Usage

compute_polygon_area(vertex.df, signed = FALSE)

Arguments

vertex.df	A data frame where each row corresponds to the vertex of a polygon. It must contain the columns x, y, and optionally group (must be integer). x and y specify the coordinates of the vertex, and group is used to indicate which polygon the vertex belongs to. If vertex.df contains only a single polygon, group can be omitted.
signed	If true, the signed areas of the polygons are returned (positive for counter-clockwise oriented polygons, negative for clockwise oriented.)

Value

A data frame that contains two columns:

group	The group number of the polygon
area	The area of the polygon

Author(s)

Mathias Isaksen [e-mail]

Examples

# Example with multiple polygons
vertex.df = compute_regular_polygons(
  center = data.frame(x = c(0, 10), y = c(0, 0)),
  radius = 1,
  num.edges = c(4, 1000)
)
area.df = compute_polygon_area(vertex.df)

# Note that the area of polygon 2 is close to pi!
print(area.df)

mathiasisaksen/artKIT documentation built on Dec. 21, 2021, 2:52 p.m.