pcds (version 0.1.2)

plotASregsTri: The plot of the Arc Slice (AS) Proximity Regions for a 2D data set - one triangle case

Description

Plots the points in and outside of the triangle tri and also the AS proximity regions for points in data set Xp.

AS proximity regions are defined with respect to the triangle tri, so AS proximity regions are defined only for points inside the triangle tri and vertex regions are based on the center M="CC" for circumcenter of tri; or \(M=(m_1,m_2)\) in Cartesian coordinates or \(M=(\alpha,\beta,\gamma)\) in barycentric coordinates in the interior of the triangle tri; default is M="CC" the circumcenter of tri.

See also (ceyhan:Phd-thesis,ceyhan:comp-geo-2010,ceyhan:mcap2012;textualpcds).

Usage

plotASregsTri(
  Xp,
  tri,
  M = "CC",
  main = "",
  xlab = "",
  ylab = "",
  xlim = NULL,
  ylim = NULL,
  ...
)

Arguments

Xp

A set of 2D points for which AS proximity regions are constructed.

tri

Three 2D points, stacked row-wise, each row representing a vertex of the triangle.

M

The center of the triangle. "CC" stands for circumcenter of the triangle tri or a 2D point in Cartesian coordinates or a 3D point in barycentric coordinates which serves as a center in the interior of the triangle \(T_b\); default is M="CC" i.e., the circumcenter of tri.

main

An overall title for the plot (default="").

xlab, ylab

Titles for the \(x\) and \(y\) axes, respectively (default="" for both).

xlim, ylim

Two numeric vectors of length 2, giving the \(x\)- and \(y\)-coordinate ranges (default=NULL for both).

…

Additional plot parameters.

Value

Plot of the AS proximity regions for points inside the triangle tri (and only the points outside tri)

References

See Also

plotASregsMT, plotPEregsTri, plotPEregsMT, plotCSregsTri, and plotCSregsMT

Examples

# NOT RUN {
A<-c(1,1); B<-c(2,0); C<-c(1.5,2);
Tr<-rbind(A,B,C);
n<-1

set.seed(1)
dat<-runif.tri(n,Tr)$g

M<-as.numeric(runif.tri(1,Tr)$g)  #try also  #M<-c(1.6,1.2);

dat<-matrix(dat,ncol=2)
Xlim<-range(Tr[,1],dat[,1])
Ylim<-range(Tr[,2],dat[,2])
xd<-Xlim[2]-Xlim[1]
yd<-Ylim[2]-Ylim[1]

plotASregsTri(dat,Tr,M,main="Proximity Regions for AS-PCD",
xlab="",ylab="",xlim=Xlim+xd*c(-.05,.05),ylim=Ylim+yd*c(-.05,.05))

plotASarcsTri(dat,Tr,main="arcs of AS-PCD", xlab="",ylab="",xlim=Xlim+c(-.05,.05),ylim=Ylim)

if (dimension(M)==3) {M<-bary2cart(M,Tr)}
#need to run this when M is given in barycentric coordinates

CC<-circ.cent.tri(Tr)
if (isTRUE(all.equal(M,CC)) || identical(M,"CC"))
{cent<-CC
D1<-(B+C)/2; D2<-(A+C)/2; D3<-(A+B)/2;
Ds<-rbind(D1,D2,D3)
cent.name<-"CC"
} else
{cent<-M
cent.name<-"M"
Ds<-cp2e.tri(Tr,M)
D1<-Ds[1,]; D2<-Ds[2,]; D3<-Ds[3,]
}

plotASregsTri(dat,Tr,M,main="Proximity Regions for AS-PCD",xlab="",ylab="")
L<-rbind(cent,cent,cent); R<-Ds
segments(L[,1], L[,2], R[,1], R[,2], lty=2)

txt<-rbind(Tr,cent,Ds)
xc<-txt[,1]+c(-.02,.03,.03,.03,.05,-0.03,-.01)
yc<-txt[,2]+c(.02,.02,.02,.07,.02,.05,-.06)
txt.str<-c("A","B","C",cent.name,"D1","D2","D3")
text(xc,yc,txt.str)

# }