GfsOutputGRD
From Gerris
OutputGRD writes a raster (or gridded) dataset using the ESRI grid ASCII format. This is typically used to import 2D fields into a GIS application.
The syntax in parameter files is:
[ GfsOutputScalar ]
By default the grid "pixels" are the square cells at the highest level of refinement. The level of the cells taken into account can be controlled using the maxlevel
option of GfsOutputScalar. Setting maxlevel
can also be useful to control the size (in grid points) of the file produced: when maxlevel
is set the size of the grid will always be a multiple (depending on the number of boxes in the computation domain) of 2^maxlevel. This holds even when the number of levels in the simulation changes due to adaptive refinement.
The NODATA
keyword of GfsFunction can be used to set the "nodata_value" mask. For example exporting only the positive values of the pressure could be written:
OutputGRD { start = end } end.asc { v = (P > 0 ? P : NODATA) }
Note that this object is only available for 2D simulations.
Tips
GRD files can be converted to more compact raster formats using GDAL. GDAL can be installed using
sudo apt-get install gdal-bin
For example conversion to GeoTIFF can be done using
gdal_translate -of GTiff -a_srs EPSG:4326 -co COMPRESS=DEFLATE -co ZLEVEL=9 output.grd output.tif