TriangleInfo: Triangle Information

In geophys: Geophysics, Continuum Mechanics, Gravity Modeling

Description

Given a triangle (three non-colinear points, return info that is useful

Usage

TriangleInfo(P1, P2 = c(0, 1), P3 = c(1, 0), add = FALSE)

Arguments

P1	vector or list(x,y) of 2D point 1
P2	vector or list(x,y) of 2D point 2
P3	vector or list(x,y) of 2D point 3
add	logical, if TRUE add a variety of lines to the plot

Details

If either P1 P2 or P3 are an x,y list, they are converted to vectors.

If P2 and P3 are missing, P1 contains all the points. Input can be list of 3 x,y values, a 3 by 2 matrix .

Value

list

BI	x,y location of center of inscribed circle
CIRCUM	x,y location of center of circumscribed circle
IH	x,y location of Intersection of bisectors
CEN	centroid location
r	radius of inscribed circle
R	radius of circumscribed circle
AngBis	loci of vectors bisecting each corner on opposite leg
H	lengths of altitudes
M	lengthsof medians
TEE	lengths of perpendiculars
Area	Area of triangle

Author(s)

Jonathan M. Lees<[e-mail]>

References

<http://en.wikipedia.org/wiki/Triangle_center>

<http://en.wikipedia.org/wiki/Encyclopedia_of_Triangle_Centers>

See Also

Intersect2points, Sect2vex, AXB.prod, TriangleCenter, rot2Zplane

Examples

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

  

theX = c(P1[1],P2[1], P3[1])
theY = c(P1[2],P2[2], P3[2])


        plot(theX , theY, asp=1)
        
        
        points(theX , theY)
        text(theX , theY, labels=1:3, pos=3)
        lines(c(theX, theX[1]), c(theY, theY[1]) )

TriangleInfo(P1, P2, P3, add=TRUE)
#####    TriangleInfo(rbind(P1, P2, P3),   add=TRUE)

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