Integer order Hankel transform

This routine implements Hankel transforms of integer order based on a Fourier-Bessel series expansion. The algorithm is based on a recently published research work:
M. Guizar-Sicairos and J. C. Gutierrez-Vega, Computation of quasi-discrete Hankel transforms of integer order for propagating optical wave fields,
J. Opt. Soc. Am. A 21, 53-58 (2004).
The numerical method features great accuracy and is energy preserving by construction, it is especially suitable for iterative transformation
processes.
With the c.mat array, that contains Bessel functions zeros, Hankel transforms of order 0-4 may be computed, with up to 3000 sampling points. A trasformation, and inverse transformation example is given.

This routine was tested under MATLAB 6.5 R13