NinePointCircle: Nine Point Circle

In geophys: Geophysics, Continuum Mechanics, Gravity Modeling

Description

Nine Point cirlce of a triangle

Usage

NinePointCircle(P1, P2 = c(0, 1), P3 = c(1, 0), add = FALSE, SHOW = TRUE)

Arguments

P1	vector, Point 1
P2	vector, Point 1
P3	vector, Point 1
add	add to existing plot
SHOW	create a new plot and add

Details

circle passes through nine points that can be calculated for any triangle. Also known as Feuerbach's circle, Euler's circle, Terquem's circle, the six-point circle, the twelve-point circle, the n-point circle, the medioscribed circle, the mid circle, the circum-midcircle.

Value

list of essential points:

A	2-vector, vertex point 1
B	2-vector, vertex point 2
C	2-vector, vertex point 3
D	2-vector, mid-point opposite A
E	2-vector, mid-point opposite B
F	2-vector, mid-point opposite C
G	2-vector, foot altitude point opposite A
H	2-vector, foot altitude point opposite B
I	2-vector, foot altitude point opposite C
J	2-vector, mid point from S-A
K	2-vector, mid point from S-B
L	2-vector, mid point from S-C
S	2-vector, Intersection point of altitudes
CEN	2-vector, center of nine point circle
R	radius of nine point circle

Author(s)

Jonathan M. Lees<[e-mail]>

References

<http://en.wikipedia.org/wiki/Nine-point_circle>

See Also

TriangleInfo, TriangleCenter

Examples

  P1 = 10*runif(2)
      P2 =  10*runif(2)
      P3 =  10*runif(2)

      TRI =  NinePointCircle(P1, P2, P3, add=TRUE, SHOW=TRUE)

geophys documentation built on May 1, 2019, 9:26 p.m.