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

1 2 3 4 5 6 |

`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. |

`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.

Karline Soetaert <karline.soetaert@nioz.nl>

`getellipse`

, `filledellipse`

,
`plotcircle`

.

1 2 3 4 5 6 7 8 9 10 11 | ```
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))
``` |

Questions? Problems? Suggestions? Tweet to @rdrrHQ or email at ian@mutexlabs.com.

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