in.circle {pcds}

Check whether a point is inside a circle

Description

Checks if the point p lies in the circle with center cent and radius rad, denoted as C(cent,rad). So, it returns 1 or TRUE if p is inside the circle, and 0 otherwise.

boundary is a logical argument (default=FALSE) to include boundary or not, so if it is TRUE, the function checks if the point, p, lies in the closure of the circle (i.e., interior and boundary combined) else it checks if p lies in the interior of the circle.

Usage

in.circle(p, cent, rad, boundary = TRUE)

Arguments

p

A 2D point to be checked whether it is inside the circle or not.

cent

A 2D point in Cartesian coordinates which serves as the center of the circle.

rad

A positive real number which serves as the radius of the circle.

boundary

A logical parameter (default=TRUE) to include boundary or not, so if it is TRUE, the function checks if the point, p, lies in the closure of the circle (i.e., interior and boundary combined); else, it checks if p lies in the interior of the circle.

Value

Indicator for the point p being inside the circle or not, i.e., returns 1 or TRUE if p is inside the circle, and 0 otherwise.

Author(s)

Elvan Ceyhan

See Also

in.triangle, in.tetrahedron, and on.convex.hull from the interp package for documentation for in.convex.hull

Examples

cent<-c(1,1); rad<-1; p<-c(1.4,1.2)
#try also cent<-runif(2); rad<-runif(1); p<-runif(2);

in.circle(p,cent,rad)

p<-c(.4,-.2)
in.circle(p,cent,rad)

p<-c(1,0)
in.circle(p,cent,rad)
in.circle(p,cent,rad,boundary=FALSE)