SteinerChain {PlaneGeometry}

Steiner chain

Description

Return a Steiner chain of circles.

Usage

SteinerChain(c0, n, phi, shift, ellipse = FALSE)

Arguments

c0

exterior circle, a Circle object

n

number of circles, not including the inner circle; at least 3

phi

-1 < phi < 1 controls the radii of the circles

shift

any number; it produces a kind of rotation around the inner circle; values between 0 and n cover all possibilities

ellipse

logical; the centers of the circles of the Steiner chain lie on an ellipse, and this ellipse is returned as an attribute if you set this argument to TRUE

Value

A list of n+1 Circle objects. The inner circle is stored at the last position.

Examples

c0 <- Circle$new(c(1,1), 3)
chain <- SteinerChain(c0, 5, 0.3, 0.5, ellipse = TRUE)
plot(0, 0, type = "n", asp = 1, xlim = c(-4,4), ylim = c(-4,4))
invisible(lapply(chain, draw, lwd = 2, border = "blue"))
draw(c0, lwd = 2)
draw(attr(chain, "ellipse"), lwd = 2, border = "red")