Regular grid not available

[suhasdl]

Hello all,

I'm trying to use the spherical transforms for the regular grid. But I'm getting a runtime error : regular grid not available (DCT required)

However everything works fine for gaussian grid.

This error is also reproducible in the example script shallow_water.py when grid is changed to regular from gaussian.

Thanks,

Suhas

[Nathanaël Schaeffer]

Hi,

Regular grid is now deprecated. You can download a previous version, or do

./configure --enable-dct

By the way, why do you need a regular grid? If there is interest in it, I may give it more love. Cheers,

[suhasdl]

Thanks for the reply.

For the latest version ./configure --enable-dct yields configure: WARNING: unrecognized options: --enable-dct

Also using the previous versions yields the following error AttributeError: 'module' object has no attribute 'sht_orthonormal'.

I have a CESM CAM simulation data which are on regular grids. I thought it would be easier to use the spherical transforms defined for that regular grid instead of interpolating the data to a gaussian grid.

[Nathanaël Schaeffer]

Hi,

Sorry for the late answer. I must investigate this issue further but have absolutely no time for another week at least.

Regular grids are not in a good shape right now. This will improve in the forthcoming months.

For now, I'd recommend interpolating and using Gauss grids. Or maybe look at the competition. I think libsharp handles regular grids well.

[suhasdl]

Hi, Thanks for responding. I purged it and installed the v2.6.6. It works now. Anyway I had wanted the regular grids which has points at the poles. But the analysis function doesn't seem to be supported by sht_reg_poles grid. So for now I have regridded the data to a Gaussian grid.

[Nathanaël Schaeffer]

Two regular grids are now available since v2.8, one including a point at the poles. They now support analysis (but require twice the latitudinal points compared to Gauss) and are much faster to initialize.