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# Simulation dimension and orientation

## Simulation coordinate system

In general, the underlying coordinate system for the simulation is a three-dimensional cartesian coordinate system (x,y,z).
Dependent on the type of simulation, that means whether a one-, two- or three-dimensional simulation has to be performed, the corresponding number of axes has to be selected out of this triplet of coordinate directions. For these specifications, the keyword``` \$simulation-dimension ``` together with its specifiers` dimension ` and` orientation ` have to be used in the input file.

```!-----------------------------------------------------! \$simulation-dimension                      required   !  dimension                 integer         required   ! ```possible values``` 1,2,3  orientation               integer_array   required   ! ```possible values``` (1 1 1); (1 1 0); (0 1 1) .... (0 1 0); (0 0 1) \$end_simulation-dimension                  required   ! !-----------------------------------------------------!```

## Syntax parameters

```!-----------------------------------------------------! \$simulation-dimension                                 !  dimension    = i                                     !  orientation  = l m n                                 ! \$end_simulation-dimension                             ! !-----------------------------------------------------!```

whereby   `i={1,2,3}` and   ``` l={0,1} m={0,1} n={0,1}``` with``` l+m+n=i```

## Example

```!-----------------------------------------------------! \$simulation-dimension                                 !  dimension    = 2                                     !  orientation  = 1 0 1                                 ! \$end_simulation-dimension                             ! !-----------------------------------------------------!```

This specifies the number of nontrivial dimensions of the device, namely 2 in this example.  This two dimensional domain is spanned by the (x,z) coordinates of the overall three-dimensional coordinate system.

## Specification of the simulation domain dimension and its orientation:

```!-----------------------------------------------------! \$simulation-dimension                                 !    dimension   = 2                                    !    orientation = 1 0 1                                ! \$end_simulation-dimension                             ! !-----------------------------------------------------!```

Possible values for dimension are 1, 2, 3; specifying a one-dimensional, a two-dimensional or a three-dimensional simulation domain, respectively.
The specifier` orientation ` defines the orientation of the simulation domain relative to the (x,y,z) coordinate system. A three dimensional array, containing 0 and/or 1, is expected.
The 1's in this array select the relevant axes.

3-dimensional simulation
` dimension   = 3`
` orientation = 1 1 1`

2-dimensional simulations
` dimension   = 2`
``` orientation = 1 1 0  or  1 0 1  or  0 1 1```
This means, the simulation is performed in the (x,y)-plane, the (x,z)-plane or in the (y,z)-plane

1-dimensional simulation
` dimension   = 1`
``` orientation = 1 0 0  or  0 1 0  or  0 0 1```
This means, the simulation is performed along the x direction, the y-direction or the z-direction.