hi Matt
On 2/10/24 1:01 am, Matthew Knepley wrote:
On Mon, Sep 30, 2024 at 10:15 PM Adrian Croucher
<a.crouc...@auckland.ac.nz> wrote:
hi, I am testing my (Fortran) code on PETSc 3.22 and have got it to
build. However I am getting some unusual new behaviour when I
write an
IS to an HDF5 file using ISView().
The attached minimal example shows the issue. It creates a simple
10-element IS and writes it to HDF5. With previous versions of PETSc
this would give me a 10x1 dataset containing the values 0 - 9, as
expected.
When I run it with PETSc 3.22 (in serial), I again get the expected
values written on stdout, so it looks like the IS itself is
correct. But
in the HDF5 file I get a 1x3 dataset containing the values (10,1,0).
Has something changed here?
Yes. We now compress IS data sets by default. You can turn it off
using -is_view_compress 0. I am not sure
what the best way to manage this is, but it makes a huge difference in
file size for checkpointing.
Thanks. I guess that's fine if it's being read back in by PETSc, but I
have users with non-PETSc post-processing codes needing to read my
output, and they aren't going to know what to do with these compressed
datasets. I only write one IS at the start of each simulation, so it's a
negligible contribution to the file size.
So I think I will need to disable the compression in my code. Is there a
function call I can use to do that, to make sure it's always done
without users needing to pass -is_view_compress 0?
- Adrian
--
Dr Adrian Croucher
Senior Research Fellow
Department of Engineering Science
Waipapa Taumata Rau / University of Auckland, New Zealand
email:a.crouc...@auckland.ac.nz
tel: +64 (0)9 923 4611
