arrowlocator: Use the locator function to plot an arrow

In broman: Karl Broman's R Code

Use the locator function to plot an arrow

Description

Use the graphics::locator() function to indicate the endpoints of an arrow and then plot it.

Usage

arrowlocator(
  reverse = FALSE,
  horizontal = FALSE,
  vertical = FALSE,
  length = 0.1,
  ...
)

Arguments

reverse	If FALSE, first indicate the tail of the arrow and then the head; if TRUE, first indicate the head of the arrow and then the tail.
horizontal	If TRUE, force the arrow to be horizontal. (Use the average y-axis value of the two clicks for the vertical placement.)
vertical	If TRUE, force the arrow to be vertical. (Use the average x-axis value of the two clicks for the horizontal placement.)
length	Length of the edges of the arrow head.
...	Additional graphics parameters

Details

Use graphics::locator() to indicate the two endpoints of an arrow and then draw it.

Value

The locations of the endpoints of the arrow, as a two-row matrix. The first row indicates the location of the tail of the arrow; the second row indicates the location of the head of the arrow.

See Also

graphics::arrows(), graphics::locator()

Examples

## Not run: 
plot(0,0,type="n", xlab="", ylab="", xlim=c(0,100), ylim=c(0,100))
arrowlocator(col="blue", lwd=2)

## End(Not run)

broman documentation built on May 29, 2024, 7:18 a.m.