Generate cylinder with custom axis

This contribution improves an existing Matlab function, CYLINDER, by adding the possibility of defining a custom symmetry axis.
CYLINDER2 Generate cylinder with custom axis

[X,Y,Z] = CYLINDER2(R,D,N) forms the unit cylinder based on the symmetry axis D and the generator curve in the vector R. Vector R contains the radius at equally spaced points along the unit height of the cylinder. D is a vector that defines the direction of the symmetry axis. The cylinder has N points around the circumference.

[X,Y,Z] = CYLINDER2 default to R = [1 1], D = [0,0,1] and N = 20

[X,Y,Z] = CYLINDER2(R) default to D = [0,0,1] and N = 20

[X,Y,Z] = CYLINDER2(R,D) default to N = 20

SURF(X,Y,Z) displays the cylinder.

Omitting output arguments causes the cylinder to be displayed with a SURF command and no outputs to be returned.

CYLINDER2(AX,...) plots into AX instead of GCA.

Álvaro Romero Calvo 08-05-17
Partially based on MATLAB function cylinder by Clay M. Thompson
(4-24-91, CBM 8-21-92. Copyright 1984-2002 The MathWorks, Inc)