mpgrafic NEWS                                         -*- outline -*-

* Main changes in release 0.3.10 (2017-01-28) [alpha]

Debian bug #851918 for (at least) the s390x architecture
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=851918
appears to be a problem between fftw2 and openmpi, related
to the preprocessor macros MPI_COMM_F2C and FFTW_MPI_COMM_F2C,
which are intended to provide implementation-independent
conversion from fortran to C for MPI and fftw/MPI purposes.
On s390x (at least), this has the bug indicated above -
mpgrafic fails with MPI_Comm_dup reporting a fatal error.

Since mpgrafic does not require a general fftw2/openmpi
bux fix - it is a small program with only a few calls
to fftw2 - a wrapper to `rfftw3d_mpi_create_plan', the
only function subject to this bug and needed by mpgrafic,
appears to solve this bug from mpgrafic's point of view.
The two wrapper files are src/rfftw3d_mpi_create_plan_c_wrap.c
and src/wrap_rfftw3d_mod.f90. ISO_C_binding is used
to reduce the chance of future portability errors.

* Main changes in release 0.3.9 (2017-01-22) [alpha]

Previous versions stored the input `iseed' and the array `seeds'
(generated by GSL using MT19937) as fortran `integer', which
typically can be 16-bit, and on some machines might be 8-bit.
That allowed at most 65536 distinct `seeds', so on a 10,000-core
system, repeat elements of `seeds' would be extremely likely.
In 0.3.9, the C long type is used, giving about 4e9 possible
seeds. MaxRandNumStreams .eq. MaxParallelism in random.f90 limits
the stored number of seeds.

One minor reduction in printed float precision should enable the
regression test (updated) to succeed on an i386 machine.

* Main changes in release 0.3.8 (2017-01-22) [alpha]

Portability: reproducible lower precision printed floats;
iso_C_binding; avoid implementation-dependent integer sizes;
avoid implementation-dependent fortran `kind' values.
The portability improvements in 0.3.8 are only intended
to cover some of the most likely sources of portability errors,
and are unlikley to be complete.

* Main changes in release 0.3.7 (2017-01-12) [alpha]

A code regression test was added. Running this on future versions
with `make check' should detect whether code changes have caused
scientifically significant changes in the calculations.

* Main changes in release 0.3.4 (2017-01-05) [alpha]

Debianisation - a debian directory for preparing debian packets
is available in the debian downstream version 0.3.4-1 at
https://anonscm.debian.org/cgit/debian-astro/packages/mpgrafic.git/
