arrowheadr

Purpose

The arrowheadr package allows one to create custom arrowheads that can be used with the ggarrow package.

Installation

The arrowheadr package can be installed via CRAN:

install.packages("arrowheadr")

The development version of arrowheadr can be installed by running this code:

install.packages("arrowheadr", repos = c('https://wjschne.r-universe.dev'))

Example

The ggarrow package makes it possible to create a wide variety of arrows. The arrowheadr package makes it easy to create custom arrowheads.

tibble(
  theta = seq(0, 300, 60) * pi / 180,
  x = cos(theta),
  y = sin(theta)
) |>
  ggplot(aes(x, y)) +
  coord_equal() +
  geom_arrow_segment(aes(
    xend = x,
    yend = y,
    x = 0,
    y = 0
  ),
  arrow_head = arrow_head_deltoid(),
  resect = 2)

Figure 1: Using arrowheadr with ggarrow

The ggdiagram package also uses arrowheadr and ggarrow under the hood.

# Make a circle
A <- ob_circle(center = ob_point(0, 0), radius = 1)

# Make angles evenly spaced around a circle
theta <- degree(seq(0, 330, 30))

# Make ring of points around the circle
p <- ob_point() |>
  place(from = A, where = theta, sep = 2)

# Make rotated squares
B <- ob_rectangle(center = p, angle = theta)


ggdiagram() +
  A +
  B +
  # Arrows from A to B
  connect(A, 
          B, 
          resect = 2) +
  # Straight arrows from B to adjacent B
  connect(B@north, 
          B[c(2:12, 1)]@south, 
          resect = 2) +
  # Arc arrows from B to adjacent B
  connect(B[c(2:12, 1)]@east, 
          B@east, 
          arc_bend = -1, 
          resect = 2)

Figure 2: Using arrowheadr with ggdiagram