intersectionEllipseLine {PlaneGeometry}

Intersection of an ellipse and a line

Description

Return the intersection of an ellipse and a line.

Usage

intersectionEllipseLine(ell, line, strict = FALSE)

Arguments

ell

an Ellipse object or a Circle object

line

a Line object

strict

logical, whether to take into account line$extendA and line$extendB if they are not both TRUE

Value

NULL if there is no intersection; a point if the infinite line is tangent to the ellipse, or NULL if strict=TRUE and the point is not on the line (segment or half-line); a list of two points if the ellipse and the infinite line meet at two points, when strict=FALSE; if strict=TRUE and the line is a segment or a half-line, this can return NULL or a single point.

Examples

ell <- Ellipse$new(c(1,1), 5, 1, 30)
line <- Line$new(c(2,-2), c(0,4))
( Is <- intersectionEllipseLine(ell, line) )
ell$includes(Is$I1); ell$includes(Is$I2)