arctext: Display text on a circular arc

In plotrix: Various Plotting Functions

Display text on a circular arc

Description

Displays a character string on the circumference of an imaginary circle on an existing plot.

Usage

 arctext(x,center=c(0,0),radius=1,start=NULL,middle=pi/2,end=NULL,stretch=1,
 clockwise=TRUE,cex=NULL,...)

Arguments

x	A character string.
center	The center of the circular arc in x/y user units.
radius	The radius of the arc in user units.
start	The starting position of the string in radians.
middle	The middle position of the string in radians.
end	The end position of the string in radians.
stretch	How much to stretch the string for appearance.
clockwise	Whether to print the string in the clockwise direction.
cex	The character expansion factor.
...	additional arguments passed to ‘⁠text⁠’.

Details

‘⁠arctext⁠’ displays a string along a circular arc, rotating each letter. This may not work on all devices, as not all graphic devices can rotate text to arbitrary angles. The output looks best on a Postscript or similar device that can rotate text without distortion. Rotated text often looks very ragged on small bitmaps.

If the user passes a value for ‘⁠start⁠’, this will override any value passed to ‘⁠middle⁠’. If the plot area is not square, see ‘⁠par(pty="s")⁠’, the arc will be somewhat elliptical.

If the ‘⁠clockwise⁠’ argument is TRUE, the string will be displayed in a clockwise direction and the orientation of the characters will be rotated ‘⁠pi⁠’ radians (180 degrees). This is useful when the string is to be displayed on the bottom of the circumference.

Value

nil

Author(s)

Jim Lemon - Thanks to Suhas Parandekar for the idea, Ted Toal for greatly improving the placement of the text and Andy South for providing the initial code for the clockwise argument.

See Also

text

Examples

 plot(0, xlim = c(1, 5),ylim = c(1, 5),main = "Test of arctext", xlab = "",
  ylab = "", type = "n")
 arctext("bendy like spaghetti", center = c(3,3), col = "blue")
 arctext("bendy like spaghetti", center = c(3,3), radius = 1.5, start = pi,
  cex = 2)
 arctext("bendy like spaghetti", center = c(3, 3),radius = 0.5,
  start = pi/2, stretch = 1.2)
 arctext("bendy like spaghetti", center = c(3, 3), radius = 1.7,
  start = 4 * pi / 3, cex = 1.3, clockwise = FALSE)

plotrix documentation built on Nov. 10, 2023, 5:07 p.m.