[FLASH-USERS] FLASH3.1.1 Release

[Anshu Dubey]

The Flash Center is pleased to announce the release of the
next minor version of the FLASH code, version 3.1.1. FLASH 3.1.1
primarily resolves bugs found in the 3.1 release.

The most important bug resolutions in this release pertain to the
mapping of active particles to the mesh, where mapping routines used some
data from Paramesh which wasn't yet updated, resulting in potentially undefined
behavior.  There was an additional bug in the same section of the code when
calculating the block/processor/corner IDs of neighboring blocks where
a block face touches 4 neighbors at a higher refinement level (3D
simulations only).

More minor improvements and bug fixes include -

1. fidlr can read PnetCDF output files without failing

2. Bugs in implementations of Balsara's algorithm for prolonging
  divergence-free face-centered magnetic fields have been fixed.

3. A redundancy for keeping both magnetic resistivity and magnetic
  viscosity has been removed in materialProperties/MagneticResistivity
  unit. Only magnetic resistivity is being used with proper scalings
  in this release.

4. MPI tag values overflowed in PARAMESH when
  using certain MPI implementations.  This has now been resolved in pm40
  and pm4dev.  The old behavior of assigning each MPI message a unique
  tag ID can be restored by defining PM_UNIQUE_MPI_TAGS pre-processor
  definition in setup script call.

5. There was extremely poor performance when reading particle data
  from a checkpoint file on BG/P.  We revert to the old contiguous
  particle attribute read of FLASH 3.0 when particle fields are the same
  in the checkpoint file and flash3 binary to improve performance.

New additions to the code include

1. An alternative implementation of PFFT routines which map FLASH grid
data to a
   uniform Pencil grid.  This implemetation uses less memory than the
FLASH 3.1 implementation.
  Additionally there is a new file containing subroutines that operate
on a list
  datatype which may be included in any module to construct a linked
list  object
  of user-specified node types.

2. A routine to find all neighboring block/proc IDs to a particular
local block in the
    Paramesh implementation of the Grid unit.

The release is available at:

http://flash.uchicago.edu/website/download/

A stripped down version of FLASH3 that may be downloaded without a
license is also available at the same location. This version is
essentially the FLASH framework without any implementations.
Flash Center is also providing support for "add-ons" to the
code. Please see the section on "What's new in this release" in the
first chapter of the user's guide for details.