GALAXY N-body simulation code

© 2014 J. A. Sellwood, formerly Rutgers University, now Steward Observatory

This website lists the updates made in the various GALAXY software releases

A detailed description of how to install and use the code is given in the updated on-line manual

Known bugs in version 16.11

    None - v16.11 fixes all known bugs in previous versions

Updates

  1. Aug 16, 2023. Release of v16.11. Shu DFs for disks now created with an improved algorithm.
    1. The principal improvement is to the software to set up a DF by Shu's method. This part of the code has been completely rewritten - see the notes in section 15.7 on p82. The new method is both faster and better than the old, but it still requires careful management as described in "Advice to the user" (section 15.7.4).
    2. This release also makes it possible to specify the run number on the command line for most of the executables in the package. If the run number is omitted, the code still prompts for it. analys can be invoked with multiple run numbers if it is desired to compare the evolution of the first mentioned run with others.
    3. Other minor improvements are to fix little bugs and to improve parts of the analysis software as detailed in DOCS/revisions.v16.11
  2. Mar 3, 2023. Release of v16.10. This release features improvements to the derivation of a Shu DF for disks.
    1. Program smooth should be run interactively only if it is to create the DF for a disk by Shu's method using dfShuc, non-interactive runs are OK for other DFs. It creates the .dft file which is now used separately by dfShut.
    2. New functions QofR and taperR are supplied to set default profiles that can be edited by the user, if desired.
    3. A number of minor improvements to fix little bugs and to improve parts of the analysis software are also included.
  3. Sep 14, 2022. Release of v16.04. fixed 2 bugs that had been introduced in v16.0.
    1. Eliminated partial solutions for the field on polar grids, since accel dependent zones are not spatially separate. This was a bug, introduced at v16, that would have caused large changes to the total energy
    2. Another recently introduced bug that is now fixed caused failure to restart simulations that used the hybrid code on multiple processors
  4. Jun 1, 2022. Release of v16.0. Principal changes at version 16.0
    1. added acceleration-dependent criterion for time steps
    2. changed the .dat file to input the longest time step that will used, which will be reduced by successive factors of two in either spatial zones or as required by accelerations
    3. input analysis time interval and duration of the simulation to be in units of time, not steps
    4. created a blkdat segment to initialize variables in common
    5. made more use of allocatable arrays
    6. made ptcls a 2D array
    7. a number of minor bug fixes (see revisions.v16.0 in the DOCS directory)
    8. updated most of the README files, which unfortunately contained a lot of misinformation in version 15.

  5. May 25, 2020. Release of v15.4. Fixed a significant bug, found by Vance Wheeler, that caused large force errors inside the guard radius from the s3d when not all particles have the same mass. The self-force on a particle that was subtracted from s3d grid force was not scaled by the relative particle mass.
  6. July 20, 2019. Release of v15.34. Fixes of a few very minor bugs of little significance (see the changelog.txt file in the DOCS directory for a full list), but there were somewhat extensive improvements to the EXAMPLES directory in the form of updated README files and standardized scripts.

  7. May 18, 2019. Release of v15.33. Fixed array subscripting caused by different roundoff in gfortran from other compilers. This will have very occasionally, and at one random step only, caused the wrong accelerations to have been applied to particles on polar grids.

  8. February 4, 2019. Release of v15.32 Very minor update. Bug in qsetup.f fixed, tiny changes to galaxy.f and to dflook.f, and the gfortran options in the Makefile now trap floating point errors

  9. January 3, 2019. Release of v15.31.
    1. The arrays islist and s3rad, which were in common blocks admin and grids respectively are now allocatable, and therefore held in module aarrays. The local iput buffer in psetup is now allocatable also
    2. The total energy (PE + KE) of active particles now includes contributions from all active mass components - previously it was the first two only - a book-keeping error only
    3. Other improvements and minor bug fixes in GALAXY
    4. Changes in setup code
    5. Some minor improvements to plotting software

  10. August 6, 2018. Release of v15.22.
    1. The main improvement in this minor update is to the Shu DF, which now yields much better equilibria for heavy disks. In addition, it reports either success or aborts with a helpful message on failure.
    2. The user now has the option to skip creating mpi versions of the main programs. The single processor versions are still found in /progs and the Makefile in that directory no longer attempts to create mpi versions. The mpi versions have been moved to a separate directory /progs_mpi, which has its own Makefile
    3. The program smooth now asks whether to create equal mass particles before entering the number of particles to generate
    4. Subroutine msetup now reports more helpful diagnostics when there are errors in the input data
    5. Tabs in the .dat file should no longer cause read errors
    6. Two minor changes to the mpi version of galaxy are to fix little bugs, and a couple of analysis options have been improved

  11. February 6, 2018. Release of v15.20. The changes from versions 15.0 and 15.1 are again minor. The generation of real*4 random numbers caused very occasional problems and has been changed to real*8. Also anyone wishing to use guard radii on the s3d grid will need this version, since v14.2 introduced a subscripting error that has now been corrected.

  12. April 12, 2017. Release of v15.10 which elimitates the restriction that prevented creating an equilibrium disk by Shu's method in a compressed halo. The new capability can be tested by running the script EXAMPLES/hybrid/run300.s

    If you have already been working with v15.01, you can patch the code you have with the minor differences that are described in the Appendix (p84) of the revised on-line manual. First download the tar file, then cd to your GALAXY15 directory and move the downloaded file there. Then issue the command "tar xzf update15.10.tgz" which will replace the files that have been updated since v15.01. You will then need to cd SRC/lib15 and execute "rebuild", then cd ../lib15_mpi and execute "rebuild". Then cd ../progs and type "make" and then "make clean" in the usual way.

  13. March 10, 2017. Release of v15, in which all calls to NAG library routines have been eliminated. There is no update path from older versions, and this version should be installed afresh from the usual GALAXY website.

  14. v14.52, replacing v14.50, released Dec 20, 2016. If you have already been working with v14.50, or v14.511, you can patch the code you have with the minor differences that are described in the Appendix (p87) of the revised on-line manual. First download the tar file, then cd to your GALAXY directory and move the downloaded file there. Then issue the command "tar xzf update14.52.tgz" which will replace the 23 files that have been updated since v14.50. You will then need to cd CODE/lib14 and execute "rebuild", then cd ../lib14_mpi and execute "rebuild". Then cd ../progs and type "make" in the usual way.

  15. v14.511, replacing v14.50, released Nov 16, 2016. If you have already been working with v14.50, you can patch the code with the very minor differences that are described in the Appendix (p87) of the revised on-line manual. First download the tar file, then cd to your GALAXY/CODE directory and move the downloaded file there. Then issue the command "tar xzf update14.511.tgz" which will replace the 12 files that have been updated since v14.5. You will then need to cd lib14 and execute "rebuild", then cd ../lib14_mpi and execute "rebuild". Then cd ../progs and type "make" in the usual way.

  16. New release of v14.5 on May 13, 2016. It is available at the GALAXY website. The additional capabilities and improvements of this version are listed in the first Appendix (section 17) of the on-line manual.

  17. Jun 16, 2015. NAG changes The GALAXY package uses Mark 21 of the NAG library and is consistent with Marks 18 through 22. The second appendix (section 18) of the on-line manual gives instructions on very minor changes that are needed for linking with NAG Mark 17 and for Mark 23.

  18. Nov 26, 2014. The GALAXY package was updated to version 14.1, which contained a few significant improvements and also fixes one major, and a few minor, bugs. These changes are described in section 1.8 of the on-line manual.
    An existing user wishing to update to version 14.1 can either start over by downloading the entire revised GALAXY package and re-install it, or
    extract the files from this tar ball, which contains the source code of only those programs, routines and include files that were revised at this version. These files should overwrite those in the appropriate directories of the original package, which can be achieved if tar is executed in the directory "pckg". The lib14 and lib14_mpi libraries will need to be rebuilt, and the programs recompiled by rerunning 'make'.

  19. Nov 21, 2014. The first released version of subroutine loadup.f contained a serious bug that prevented multiple populations of particles from being loaded properly into the simulation code. The bug is fixed in this version, which should replace that in the directory pckg/lib14