Drawing Bezier Splines

            bezier - Cubic Bezier Spline (Interpolation) 

Calling Sequence : zi = bezier(z,NPOI,modus)  

Parameters 

 z : vector with complex values, which contains the so called weighing points. 

 NPOI : number of interpolating values. Default value is 40. 

 modus : a string, which specifies, if curves are closed ('c' or 'close') or
open       ('o' or 'open'). The default is 'close'. 

 zi : cubic bezier spline represented as a vector with complex elements 

Description 

If the weighing points are not given as complex vector, it is possible to
specify them by clicking with the mouse in a graphics window. If N weighing
points are given, the interpolation result has N*(NPOI-1) values when
modus='closed'. If modus='open', then the interpolation result has
(N-2)*(NPOI-1) values.  

Example:

z=rand(1,10,'normal') + %i .*rand(1,10,'normal');
zi=bezier(z,10,'open');
plot2d(real(z),imag(z),style=-3);
plot2d(real(zi),imag(zi),style=2);
xclick();
xbasc();
zi=bezier();