Output files
==================================

Regular Mesh Output (ASCII Text)
---------------------------------

    The output files are written to the "Results" directory. If non-existant, this folder is created during cmake run. The results are printed at the timestep defined in the Master Configuration file (variable PRINT_STEP, in seconds, e.g., 1h = 3600 seconds). The results are saved in ASCII files; one file for each time step (with the file name being the time in seconds). The basic time unit in the model is seconds. The results are printed in each column are (in order):

+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|irow [-]             |row number of cell                                                                                                                                         |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|icol[-]              |column number of cell                                                                                                                                      |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|z [m]                |water elevation above sea level (with reference to the DEM)                                                                                                |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|h [m]                |water depth                                                                                                                                                |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|ux [m/s]             |velocity in the x direction                                                                                                                                |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|uy [m/s]             |velocity in the y direction                                                                                                                                |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|qx * dxy [m3/sec]    |flow in the x direction                                                                                                                                    |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|qy * dxy [m3/sec]    |flow in the y direction                                                                                                                                    |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|us [m/s]             |sheer velocity                                                                                                                                             |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|conc_SW [mg/l]       |concentration of solute in water                                                                                                                           |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|fe_1 [m2/s]          |flow in the x direction                                                                                                                                    |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|fn_1 [m2/s]          |flow in the y direction                                                                                                                                    |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
|twetimetracer [sec]  |wet time for each cell                                                                                                                                     |
+---------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+

See :doc:`SupportingScripts` for visualization tools including the Google Earth KML exporter, VTK conversion, and more.

Triangular Mesh Output (VTK XML Unstructured Grid)
---------------------------------------------------

When using the triangular mesh (``MESH_TYPE: "triangular"``), output is written in VTK XML Unstructured Grid format (``.vtu``), which can be visualized in `ParaView <https://www.paraview.org/>`_.

**File Structure:**

.. code-block:: text

   fluxos_out/
   ├── 3600.vtu                    # Timestep at 3600 seconds
   ├── 7200.vtu                    # Timestep at 7200 seconds
   ├── 10800.vtu                   # Timestep at 10800 seconds
   ├── ...
   └── fluxos_timeseries.pvd       # ParaView time series collection

**Cell-Centered Data Arrays:**

Each ``.vtu`` file contains the triangular mesh geometry (vertices and cells) along with the following cell-centered data arrays:

.. list-table::
   :widths: 25 15 60
   :header-rows: 1

   * - Array Name
     - Units
     - Description
   * - h
     - m
     - Water depth
   * - z
     - m
     - Water surface elevation
   * - zb
     - m
     - Bed elevation
   * - ux
     - m/s
     - Velocity in x direction
   * - uy
     - m/s
     - Velocity in y direction
   * - velocity_magnitude
     - m/s
     - :math:`\sqrt{u_x^2 + u_y^2}`
   * - qx
     - m2/s
     - Unit discharge in x direction
   * - qy
     - m2/s
     - Unit discharge in y direction
   * - us
     - m/s
     - Shear velocity
   * - conc_SW_0
     - mg/l
     - Solute concentration (species 0)
   * - twetimetracer
     - s
     - Wet time tracer
   * - cell_area
     - m2
     - Cell area

**PVD Time Series File:**

The ``.pvd`` file is a ParaView Data collection file that links all timestep ``.vtu`` files into a time series for animation and temporal analysis:

.. code-block:: xml

   <?xml version="1.0"?>
   <VTKFile type="Collection" version="0.1">
     <Collection>
       <DataSet timestep="3600.0" file="3600.vtu"/>
       <DataSet timestep="7200.0" file="7200.vtu"/>
       ...
     </Collection>
   </VTKFile>

Open the ``.pvd`` file in ParaView to load all timesteps as an animation.

See :doc:`SupportingScripts` for visualization tools including the Google Earth KML exporter, ParaView workflows, and more.