[Carpet] Lower-dimensional HDF5 output?

[Thomas Radke]

Ian Hinder wrote:
> This is a feature I think would be very useful.  As far as I know, if
> you don't want to output full 3D data, the only option is to output
> ASCII, and has the problems you mentioned.  Either a standard utility
> to postprocess the ASCII files, or separate 1D and 2D HDF5 output,
> would solve these problems.  
> 
> If postprocessing, the utility should do the following:
> 
> * Eliminate data that has been output twice (was this ever fixed?)

Yes, duplicated datasets are omitted, only the last one is kept.

> * Unchunk the output
> 
> * Have the option of stripping ghost zones and buffer zones for
> visualization purposes, or keeping them for debugging (the number of
> zones would probably have to be a parameter, as it is not stored in
> the output file)

Stripping off ghost zones (and knowing how many) would be necessary only 
when chunked data needs to be merged into unchunked data during 
postprocessing. I suggest to then output unchunked data in the first 
place. Would that help ?
Implementing this feature in CarpetIOASCII would be much easier than in 
a postprocessing script.

For buffer/boundary zones there already exists the parameter 
CarpetIOASCII::out3D_outer_ghosts.

> * Work with both 1D and 2D data
> 
> There are then the separate issues of converting the 1D data into a
> format suitable for ygraph, and of merging output from
> checkpoint/recover runs, which in principle are covered by existing
> utilities.  But maybe it would be nice to merge these features into
> one utility?

Yes, currently there are separate postprocessing scripts for 
CarpetIOScalar and CarpetIOASCII output. They can probably merged into a 
single one.

-- 
Cheers, Thomas.