Bour Minimal Surface
Attributed to Edmond Bour
Equations by Roger Bagula
Graphics by Paul Bourke
February 2003

x = r^{n1} cos((n1) t)/(2 (n1))  r^{n+1} cos((n+1) t)/(2 (n+1))
y = r^{n1} sin((n1) t)/(2 (n1)) + r^{n+1} sin((n+1) t)/(2 (n+1))
z = r^{n} cos(n t) / n
0 <= r, 0 <= v <= 2 pi
