plotellipse: adds part of a colored and rotated ellipse to a plot

Description

adds (part of) a colored, and rotated ellipse to a plot; an arrow can be drawn at a specified position.

Usage

plotellipse(rx = 1, ry = 0.2, mid = c(0,0), dr = 0.01, 
            angle = 0, from = -pi, to = pi, type = "l", lwd = 2,
            lcol = "black", col = NULL, arrow = FALSE, 
            arr.length = 0.4, arr.width = arr.length*0.5, 
            arr.type = "curved", arr.pos = 1, arr.code = 2, 
            arr.adj = 0.5, arr.col = "black", ...)

Arguments

rx: long radius of ellipse.
ry: short radius of ellipse.
mid: midpoint of ellipse.
dr: size of segments, in radians, to draw ellipse (decrease for smoother).
angle: rotation angle, degrees.
from: starting angle for ellipse segment, radians.
to: final angle for ellipse segment, radians.
type: external line or points; "n" if no line.
lwd: width of external line.
lcol: line color.
col: fill color.
arrow: drawing arrowhead yes/no.
arr.length: length of arrowhead.
arr.width: width of arrowhead.
arr.type: type of arrow.
arr.pos: position of arrow, 0=start,1=end.
arr.code: integer code determining kind of arrows to draw.
arr.adj: adjustment of arrow.
arr.col: color of arrow head.
...: arguments passed to R-function lines.

Author

Karline Soetaert <karline.soetaert@nioz.nl>

Details

rx and ry are the horizontal and vertical radiusses of the ellipses.

The ellipse is drawn from the point defined by from to the point defined as to which are joined anti-clockwise.

if arrow is TRUE, an arrow is drawn along the path of the ellipse.

arr.length and arr.width set the size of the arrow.

The type of the arrowhead is set with arr.type which can take the values:

"simple" : uses comparable R function arrows.
"triangle": uses filled triangle.
"curved" : draws arrowhead with curved edges.
"circle" : draws circular head.

arr.pos, a real value between 0 and 1 gives the position (0=start,1=end).

arr.col specifies the color, arr.code specifies where the angle points to.

arr.adj specifies the position adjustment - see Arrows for details.

Examples

Run this code

emptyplot(c(-1, 1), main = "plotellipse")
plotellipse(rx = 0.8, ry = 0.3, angle = 60, col = "blue")
plotellipse(rx = 1.0, ry = 0.6, angle = 0, from = pi, to = 2*pi,
            arrow = TRUE, arr.pos = seq(0.1, 0.5, by = 0.1),
            arr.col = rainbow(5))
plotellipse(rx = 1.0, ry = 0.6, angle = 30, from = pi, to = 1.2*pi,
            col = "red")
plotellipse(rx = 0.1, ry = 0.6, from = 1.5*pi, to = pi,
            lcol = "orange", mid = c(0.2,0.2))
plotellipse(rx = 0.1, ry = 0.6, angle = 30, from = 1.5*pi, to = pi,
            lcol = "orange", mid = c(0.2,0.2))