Handling maximums for AnuGA SWW files

lutraconsulting / qgis-crayfish-plugin

Plotting and manipulating mesh data in QGIS.

http://www.lutraconsulting.co.uk/products/crayfish/

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Handling maximums for AnuGA SWW files #202

Closed saberraz closed 6 years ago

saberraz commented 8 years ago

Currently, users need to run a script to extract maximums from SWW files. Would be good to have a nice method of extracting and displaying the maximums in Crayfish.

PeterPetrik commented 8 years ago

which script? If we have the script source, it would be easily possible to add a action on results dataset to "add Maximums". This action (in right click menu) can for example go through time-varying dataset and compute maximum and add it as a new CF layer.

saberraz commented 8 years ago

2 potential problems:

Maximum values are not necessarily the maximum values stored in the SWW file. For example, if the model outputs values every 300 seconds and the actual max happens in between the 300 seconds intervals, it will not be stored.
It can take a long time to generate max values from SWW IMO, AnuGA should store the max values in a separate file or array so that it can be detected by crayfish upon loading.

saberraz commented 8 years ago

Here is the script: https://github.com/GeoscienceAustralia/anuga_core/blob/5b3fe98861b2e9a91beb0cee21db68d8258a0bb9/anuga/file_conversion/sww2dem_new.py

and an example: https://github.com/GeoscienceAustralia/anuga_core/blob/master/examples/cairns/export_results.py

saberraz commented 8 years ago

From the ANUGA developer's mail:

ANUGA has an operator anuga.operators.collect_max_quantities_operator which can be used to store the maximum at every timestep (not just sww output timesteps).

For an example of its usage, see anuga_core/examples/cairns_excel/run_model.py

At the moment this operator only provides optional csv export of the maxima -- they don't go to netcdf.

saberraz commented 8 years ago

We have 2 options:

Create a mesh and populate the csv values
Create a geo-tiff

The first option is ideal as there will be no interpolation and the values are related to the native mesh element.

I still think it makes more sense to have it as a dummy time step within the netcdf result or as an external netcdf file. That's how majority of the modelling packages handle max values.

PeterPetrik commented 6 years ago

From Crayfish 3.x release and QGIS 3.4 release, the rendering and styling is implemented in QGIS Core. The data reading and support is implemented in MDAL. Please reopen the ticket in QGIS bug tracker for rendering issues or MDAL for format support issues. Thanks.