circum: Determine the circumcircle of a triangle

In tripack: Triangulation of Irregularly Spaced Data

Description

This function returns the circumcircle of a triangle.

Usage

circum(x, y)

Arguments

x	Vector of three elements, giving the x coordinatres of the triangle nodes.
y	Vector of three elements, giving the y coordinatres of the triangle nodes.

Details

This is an interface to the Fortran function CIRCUM found in TRIPACK.

Value

x	'x' coordinate of center
y	'y' coordinate of center
radius	circumcircle radius
signed.area	signed area of riangle (positive iff nodes are numbered counter clock wise)
aspect.ratio	ratio "radius of inscribed circle"/"radius of circumcircle", varies between 0 and 0.5 0 means collinear points, 0.5 equilateral trangle.

Note

This function is mainly intended to be used by circumcircle.

Author(s)

Fortran code: R. J. Renka, R code: A. Gebhardt

References

R. J. Renka (1996). Algorithm 751: TRIPACK: a constrained two-dimensional Delaunay triangulation package. ACM Transactions on Mathematical Software. 22, 1-8.

See Also

circumcircle

Examples

circum(c(0,1,0),c(0,0,1))

Example output

$x
[1] 0.5

$y
[1] 0.5

$radius
[1] 0.7071068

$signed.area
[1] 0.5

$aspect.ratio
[1] 0

tripack documentation built on July 8, 2020, 5:59 p.m.