SetBoundaryCond
===============
```{function}  SetBoundaryCond(FDTD, BC, varargin)
```
Full definition:
```{code-block} matlab
FDTD = SetBoundaryCond(FDTD, BC, varargin)
```

    BC = [xmin xmax ymin ymax zmin zmax];

or

    BC = {xmin xmax ymin ymax zmin zmax};

?min/?max: 

- 0 = PEC      or  'PEC'
- 1 = PMC      or  'PMC'
- 2 = MUR-ABC  or  'MUR'
- 3 = PML-ABC  or  'PML_x' with pml size x => 4..50

example:

    BC = [ 1     1     0     0     2     3     ]  %using numbers or
    BC = {'PMC' 'PMC' 'PEC' 'PEC' 'MUR' 'PML_8'}  %using equivalent strings

mur-abc definitions
define a phase-velocity to be used by the mur-abc
useful e.g. for dispersive waveguides

    FDTD = SetBoundaryCond(FDTD,BC,'MUR_PhaseVelocity',299792457.93272);

pml definitions arguments: 
  - 'PML_Grading','gradFunction'
    - Define the pml grading grading function.
  - Predefined variables in this grading function are:
    - D  = depth in the pml in meter
    - dl = mesh delta inside the pml in meter
    - W  = width (length) of the pml in meter
    - N  = number of cells for the pml
    - Z  = wave impedance at the current depth and position

example: 

  FDTD = SetBoundaryCond(FDTD,BC); 

or

  FDTD = SetBoundaryCond(FDTD,BC,'PML_Grading','-log(1e-6)*log(2.5)/(2*dl*pow(2.5,W/dl)-1) * pow(2.5, D/dl) / Z');




-----------------------
author: Thorsten Liebig