AddWaveGuidePort
================
```{function}  AddWaveGuidePort( CSX, prio, portnr, start, stop, dir, E_WG_func, H_WG_func, kc, exc_amp, varargin )
```
Full definition:
```{code-block} matlab
function [CSX,port] = AddWaveGuidePort( CSX, prio, portnr, start, stop, dir, E_WG_func, H_WG_func, kc, exc_amp, varargin )
```

Create a waveguide port, including an optional excitation and probes

Note: - The excitation will be located at the start position in the given direction
      - The voltage and current probes at the stop position in the given direction

parameter:
- CSX:        complete CSX structure (must contain a mesh)
- prio:       priority of primitives
- start:      start coordinates of waveguide port box
- stop:       stop  coordinates of waveguide port box
- dir:        direction of port (0/1/2 or 'x'/'y'/'z'-direction)
- E_WG_func:  electric field mode profile function as a string
- H_WG_func:  magnetic field mode profile function as a string
- kc:         cutoff wavenumber (defined by the waveguide dimensions)
- exc_amp:    excitation amplitude (set 0 to be passive)

optional (key/values):
- varargin:   optional additional excitations options, see also AddExcitation
- 'PortNamePrefix': a prefix to the port name

output:
- CSX:        modified CSX structure
- port:       port structure to use with calcPort

example:

    % create a TE11 circular waveguide mode, using cylindircal coordinates
    p11 = 1.841;
    kc = p11 / radius;  % cutoff wavenumber with radius in meter
    kc_draw = kc*unit;  % cutoff wavenumber in drawing units

    % electric field mode profile
    func_E{1} = [ num2str(-1/kc_draw^2,15) '/rho*cos(a)*j1('  num2str(kc_draw,15) '*rho)'];
    func_E{2} = [ num2str(1/kc_draw,15) '*sin(a)*0.5*(j0('  num2str(kc_draw,15) '*rho)-jn(2,'  num2str(kc_draw,15) '*rho))'];
    func_E{3} = 0;

    % magnetic field mode profile
    func_H{1} = [ '-1*' num2str(1/kc_draw,15) '*sin(a)*0.5*(j0('  num2str(kc_draw,15) '*rho)-jn(2,'  num2str(kc_draw,15) '*rho))'];
    func_H{2} = [ num2str(-1/kc_draw^2,15) '/rho*cos(a)*j1('  num2str(kc_draw,15) '*rho)'];
    func_H{3} = 0;

    start=[mesh.r(1)   mesh.a(1)   0  ];
    stop =[mesh.r(end) mesh.a(end) 100];
    [CSX, port{1}] = AddWaveGuidePort(CSX, 0, 1, start, stop, 2, func_E, func_H, kc, 1);



-----------------------
(c) 2013 Thorsten Liebig (thorsten.liebig@gmx.de)

See also InitCSX, AddExcitation, calcWGPort, calcPort