Gmisc (version 3.0.3)

bezierArrowSmpl: A simple bezier arrow

Description

This is an alternative to the grid packages bezierGrob with the advantage that it allows you to draw an arrow with a specific unit width. Note, it has only a end-arrow at this point.

Usage

bezierArrowSmpl(
  x = c(0.2, 0.7, 0.3, 0.9),
  y = c(0.2, 0.2, 0.9, 0.9),
  width = 0.05,
  clr = "#000000",
  default.units = "npc",
  arrow = list(),
  rez = 200,
  align_2_axis = TRUE,
  name = NULL,
  rm_intersect = 3L,
  gp = gpar(),
  vp = NULL
)

Value

grid::grob A grob of the class polygonGrob with attributes that correspond to the bezier points.

Arguments

x

A numeric vector or unit object specifying x-locations of spline control points.

y

A numeric vector or unit object specifying y-locations of spline control points.

width

The width of the arrow, either a numeric single number or a unit. Note: The arrow does not rely on lwd but on actual width.

clr

The color of the arrow.

default.units

A string indicating the default units to use if x or y are only given as numeric vectors.

arrow

This is a list with all the base (width) and the desired length for the arrow. Note: This differs from the original bezierGrob function.

rez

The resolution of the arrow. This specifies how many points to retrieve from the gnrlBezierPoints function. Defaults to 200.

align_2_axis

Indicates if the arrow should be vertically/horizontally aligned. This is useful for instance if the arrow attaches to a box.

name

A character identifier.

rm_intersect

Set to 0 if you want to skip intersection removal, 1 only to remove left or 2 to only remove right. See details for why.

@section Remove intersections:

When the line is wide and the arrow has a narrow curve there may appear an empty triangle due to polygon cancellation (two polygons within the same are cancel out). This behaviour may be ugly and the function therefor tries to remove these.

Note: it is expensive to check if there are the lineas may intersect at one point, remove those unexpected, and then adjust the line to the new situation so that the top and bottom lines match. It can also cause some unexpected behaviour why you may want to remove this feature if the arrow behaves erratically.

gp

An object of class "gpar", typically the output from a call to the function gpar. This is basically a list of graphical parameter settings.

vp

A Grid viewport object (or NULL).

Examples

library(grid)
grid.newpage()
arrowGrob <- bezierArrowSmpl(
  x = c(.1, .3, .6, .9),
  y = c(0.2, 0.2, 0.9, 0.9)
)
grid.draw(arrowGrob)