next up previous index
Next: Boundary conditions Up: Choice of grids and Previous: Input grid(s) for transport   Index

Output grids

SWASH can provide output on uniform, rectilinear grids that are independent from the input grids and from the computational grid. In the computation with an orthogonal curvilinear computational grid, curvilinear output grids are available in SWASH. An output grid has to be specified by the user with an arbitrary resolution, but it is of course wise to choose a resolution that is fine enough to show relevant spatial details. It must be pointed out that the information on an output grid is obtained from the computational grid by bi-linear interpolation (output always at computational time level). This implies that some inaccuracies are introduced by this interpolation. It also implies that bottom or wind information on an output plot has been obtained by interpolating twice: once from the input grid to the computational grid and once from the computational grid to the output grid. If the input, computational and output grids are identical, then no interpolation errors occur.


In the regions where the output grid does not cover the computational grid, SWASH assumes output values equal to the corresponding exception value. For example, the default exception value for the surface elevation is -9. The exception values of output quantities can be changed by means of the QUANTITY command.


Output can be requested at regular intervals starting at a given time always at computational times.


next up previous index
Next: Boundary conditions Up: Choice of grids and Previous: Input grid(s) for transport   Index
The SWASH team 2017-04-06