How to draw an open polygon in R

Question

How can I create open polygons using R like these two examples:

This question is a little vague. Do you mean how do create open polygons in R's plotting environment? — Mosquite, Aug 09 '17 at 18:10
Yes in R plotting environment. Ggplot2 is not absolutely necessary. — sbac, Aug 09 '17 at 18:21

Dave Gruenewald · Accepted Answer · 2017-08-09T18:41:26.453

A little vague on what your use will be for this, but geom_path within the package ggplot2 is a fairly simple approach.

First create a data frame, with x and y being your cartesian coordinates for all vertices:

df <- data.frame(plot = c(rep(1, 3), rep(2, 4)),
                 x = c(1, 0, 2, 0.5, 0, 2, 2.5),
                 y = c(1, 0, 0, 1, 0, 0, 1))

Now plot:

library(ggplot2)

ggplot(data = df, aes(x = x, y = y, group = 1)) +
  geom_path(size = 1) + 
  facet_grid(. ~ plot) +
  theme_bw()

If you want more flexibility with customization, I suggest you create a separate, more detailed question.

score 2 · Answer 2 · answered Aug 09 '17 at 21:42

2

If you do not want to use ggplot you can do a similar thing as @DaveGruenewald with the native plot function.

Just do:

plot(c(0.5, 0, 2), c(1, 0, 0), type='l')
plot(c(0.5, 0, 2, 2.5), c(1, 0, 0, 1), type='l')

to get plots similar to @DaveGruenewald.

answered Aug 09 '17 at 21:42

Mosquite

2 Answers2