PostGrid2Grid
-------------

Description
~~~~~~~~~~~

``PostGrid2Grid`` is a HOS post-processing class. It generates 3D VTK files of wave fields for visualization and wave elevation time series computed from ``Vol2Vol`` class. Wave fields at desired simulation time and spatial domain and wave elevation time series can be re-generated at some provided wave probes position.

``PostGrid2Grid`` algorithm is depicted in :numref:`fig:postGrid2GridAlgorighm`. ``PostGrid2Grid`` is initialised with input file. The input file ``postGrid2Grid.dict`` contains HOS grid information and post processing information which have dictionary format. ``PostGrid2Grid`` first reads and checks the input file and then build 3D visualization grid and wave probes. ``Vol2Vol`` class is also initialised. The subroutine ``doPostProcessing`` do time loop of ``correct``. Subroutine ``correct`` first corrects the ``Vol2Vol`` class and gets the wave fields. If the grid option is set to no air mesh, 3D grid is fitted to wave elevation. It writes the results on files (3D VTK file and wave elevation time series).

.. figure:: figures/c1.structure/postGrid2Grid_Algorithm.png
   :alt: ``PostGrid2Grid`` Algorithm
   :name: fig:postGrid2GridAlgorighm

   ``PostGrid2Grid`` Algorithm

Class(Type)
~~~~~~~~~~~

**Class** : ``PostGrid2Grid``

- Data :

    - ``hosVol2Vol_`` : ``Vol2Vol`` class
    - ``rectLGrid_`` : Rectangular linear grid for 3D wave fields (VTK output)
    - ``waveProbe_(:)`` : Wave probe

- Functionality (Public) :

    - ``initialize`` : Initialise PostGrid2Grid class
    - ``correct`` : Correct ``Vol2Vol``, ``rectLGrid_`` and ``waveProbe_`` and write output
    - ``writeVTK`` : Write 3D wave fields in VTK format
    - ``doPostProcessing`` : Do post processing
    - ``destroy`` : Destuctor of PostGrid2Grid class

- Functionality (Private) :

    - ``readPostG2GInputFileDict`` : Read ``PostGrid2Grid`` input file
    - ``checkPostG2GParameter`` : Check ``PostGrid2Grid`` input file
    - ``writeVTKtotalASCII`` : Write wave fields (Including air domain)
    - ``writeVTKnoAirASCII`` : Write wave fields (Grid is fitted to wave elevation)
    - ``writeWaveProbe`` : Write wave elevation time series

Input File of PostGrid2Grid
~~~~~~~~~~~~~~~~~~~~~~~~~~~

``PostGrid2Grid`` needs the input file. The input file name is ``postGrid2Grid.dict``. The input is recognized by ``dictionary(keyword + value with sub-dictionary)``. The special characters are treated as a comment (``!, # and \\``) and C++ style comment block is also allowed.

- PostGrid2Grid variables

.. code:: bash


       ### Select HOS dictionary and set post processing option ----------------------------------- #

       Grid2Grid                   HOSDict;    # HOS dictionary

       writeVTK                    true;   # 3D visualization option; true or false

       writeWaveProbe      true;   # Wave probe option; true or false

- HOS dictionary

.. code:: bash


       ### HOS dictionary ----------------------------------- #

       HOSDict
       {
           type    Ocean;      # HOS solver type; NWT or Ocean

           filePath    example/modes_HOS_SWENSE.dat;   # HOS file path

           fileType    ASCII;  # Option; HOS result file type, ASCII or HDF5

           interpolationOrder  3;  # Option; 3:Cubic spline [Default]

           zMin        -0.6;       # HOS domain zMin
           zMax        0.6;        # HOS domain zMax

           nZMin       50;     # HOS domain nZMin
           nZMax       50;     # HOS domain nZMax

           zMeshType   meshRatio;      # Mesh type (uniform, sine, meshRatio)

           zMinRatio   3.0;    # Option, z<=0 meshing ratio (meshRatio)
           zMaxRatio   3.0;    # Option, z<=0 meshing ratio (meshRatio)

           writeLog        true;   # Option; write log option
       }

- Simulation Dictionary

.. code:: bash


       ### Simulation dictionary ------------------------------------------- #

       simulation
       {
           startTime       2712.0;

           endTime         2812.0;

           dt              0.1;
       }

- 3D visualization dictionary

.. code:: bash


       ### VTK mesh dictionary ------------------------------ #

       vtkMesh
       {
           airMesh     false;      # Air meshing option

           xMin         0.0;           # VTK mesh xMin
           xMax        100.0;      # VTK mesh xMax

           yMin         0.0;           # VTK mesh yMin
           yMax        100.0;      # VTK mesh yMax

           nX          50;             # VTK mesh nX
           nY          50;             # VTK mesh nX

           zMin        -0.6;           # VTK mesh zMin
           zMax        0.6;            # VTK mesh zMax

           nZMin       50;             # VTK mesh nZMin
           nZMax       50;             # VTK mesh nZMax

           zMeshType   meshRatio;      # Mesh type (uniform, sine, meshRatio)

           zMinRatio   3.0;    # Option, z<=0 meshing ratio (meshRatio)
           zMaxRatio   3.0;    # Option, z<=0 meshing ratio (meshRatio)

       }

- Wave probe dictionary

.. code:: bash


       ### Wave probe dictionary ------------------------------------------ #

       waveProbe
       {
           waveProbeFile   waveElevation.dat;      # Output file name

           waveProbes
           {
               probe1
               {
                   position  ( 0.0   10.0 );       # wave probe position
               }
               probe2
               {
                   position  ( 0.0   15.0 );
               }
           }
       }

How to use
~~~~~~~~~~

.. code:: fortran


       !! Subroutine to run PostGrid2Grid -----------------------------------
       Subroutine runPostGrid2Grid(inputFileName)
       !! -------------------------------------------------------------------
       Use modPostGrid2Grid                    !! Use PostGrid2Grid Module
       !! -------------------------------------------------------------------
       Implicit none
       Character(Len = * ),intent(in) :: inputFileName     !! postGrid2Grid.inp
       Type(typPostGrid2Grid)         :: postG2G               !! postGrid2Grid Class
       !! -------------------------------------------------------------------

       !! Initialize PostGrid2Grid with Input File
       Call postG2G%initialize(inputFileName)

       !! Do Post Processing
       Call postG2G%doPostProcessing()

       !! Destroy
       Call postG2G%destroy

       !! -------------------------------------------------------------------
       End Subroutine
       !! -------------------------------------------------------------------