FreeEOS is a Fortran library for calculating the equation of state using an
efficient free-energy minimization technique that is suitable for physical
conditions in stellar interiors. This code is licensed under the GPL.
Stable releases
and
documention
of FreeEOS are both available.
News
-
2008-07-08: FreeEOS-2.2.1 has been released! The new release fixes all
known bugs in FreeEOS-2.2.0 and has
negligible changes compared
to FreeEOS-2.1.0, the last recommended release of FreeEOS. Calculations
based on the new release converge for conditions significantly more dense
than a 0.1-solar mass model, the approximate convergence limit for
FreeEOS-2.1.0. However, the EOS1 free-energy model needs
adjustment (still a work in progress) before it can produce smooth results at
such high densities.
See this announcement for details.
-
2008-06-22: Wider testing of FreeEOS-2.2.0 shows a number of bugs were
introduced by the 2.2.0 code reorganization. FreeEOS-2.2.0 is no
longer recommended. Use FreeEOS-2.1.0 until FreeEOS-2.2.1 (the planned
bugfix release for 2.2.0) is released.
-
2007-07-24: A paper entitled "The FreeEOS Code for Calculating the Equation
of State for Stellar Interiors V: Improvements in the Convergence Method"
has been made available for download.
-
2007-07-24: FreeEOS-2.2.0 has been released! The new release has an
improved implementation of the EOS1 free-energy model which leads to
systematic but negligible changes compared
to previous results. It also has a more robust convergence technique which
allows FreeEOS calculations to converge for conditions significantly more
dense than a 0.1-solar mass model. See
this announcement for details concerning the new release which will
be used primarily as a benchmark for the next more interesting release where
I plan a significant adjustment of the EOS1 free-energy model.
-
2007-07-20: The figures in Papers I,
II, III, and
IV have been upgraded using the forthcoming
FreeEOS-2.2.0 release and the latest svn version of
PLplot, the scientific plotting package
used to generate the figures for these papers.
-
2007-06-17: FreeEOS-2.1.0 has been released! The new release has a
different API (a status code is returned when the EOS calculation fails
to converge) and uses the new CMake-based build system but should produce
identical results to FreeEOS-2.0.0. See
this announcement
for details concerning the new release which will be used primarily as
a benchmark for more interesting future releases.
-
2007-03-31: I have switched our SourceForge repository from CVS to
its much better replacement, Subversion. If you are interested in using
the experimental version of FreeEOS that is the precursor to the next
release, then follow these directions to get access
to the FreeEOS experimental source code at SourceForge.
-
2007-01-26: Changed from an autotools-based build system (configure ...) to
a CMake-based build system (cmake ...). This will affect the next release.
If you want to build the current experimental CVS version (SVN version
as of 2007-03-31), the CMake
build instructions are given
in the
README file.
To learn more background information about CMake, consult
these useful links that have been collected by the PLplot developers.
-
2006-01-15: FreeEOS-2.0.0 has been released! See
this figure
to show the negligible differences in results
with FreeEOS-1.6.0. See
this announcement
for details concerning the new release which implements a significantly
faster iteration procedure.
-
2005-09-01: FreeEOS-1.6.0 has been released! See
this figure
for a pressure comparison
with FreeEOS-1.5.0. See
this announcement
for details concerning the new release which implements a change
in the adopted physical constants for FreeEOS.
-
2005-08-29: FreeEOS-1.5.0 has been released! See
this figure
for a pressure comparison
with FreeEOS-1.4.0. See
this announcement
for details concerning the new release which implements the exchange
treatment discussed in Paper IV.
-
2005-08-28: A paper entitled "The FreeEOS Code for Calculating the
Equation of State for Stellar Interiors IV: The Treatment of the Exchange
Effect" has been made available for
download.
-
2005-04-22: A paper entitled "The FreeEOS Code for Calculating the
Equation of State for Stellar Interiors III: The Treatment of the Coulomb
Correction" has been made available for
download.
-
2005-04-22: FreeEOS-1.4.0 has been released! See
this figure
for a pressure comparison
with FreeEOS-1.3.0. See
this announcement
for details concerning the new release which implements the Coulomb
treatment discussed in Paper III.
-
2005-02-21: FreeEOS-1.3.0 has been released! See
this figure
for a pressure comparison
with FreeEOS-1.2.0. See
this announcement
for details concerning the new release which implements an improvement
in the Fermi-Dirac integral approximations discussed in
Paper I.
-
2005-02-20: FreeEOS-1.2.0 has been released! See
this figure
for a pressure comparison
with FreeEOS-1.1.0. See
this announcement
for details concerning the new release.
-
2005-02-01: The figures in Papers I and
II have been upgraded with improved
line weight, colors, and especially fonts. The improved fonts in the
figures are a result of a recent upgrade to the CVS version of
PLplot, the scientific plotting package
used to generate the figures for these papers.
-
2004-12-20: A paper entitled "The FreeEOS Code for Calculating the
Equation of State for Stellar Interiors II: Efficient Solution Using the
Equilibrium-Constant Approach" has been made available for
download.
-
2004-10-14: A link to new documentation of the free_eos_test code is made
available on the reorganized
documentation page.
-
2004-10-09: A paper entitled "The FreeEOS Code for Calculating the
Equation of State for Stellar Interiors I: An Improved EFF-Style
Approximation for the Fermi-Dirac Integrals" has been made available for
download.
-
2004-10-09: Establish this web page for FreeEOS.
-
2004-10-08: New autotools-based build system for the forthcoming release of
FreeEOS tested successfully on Linux, AIX, and Solaris.
-
2004-09-17: FreeEOS-1.1.0
released. This is a snapshot of my stable code
base as of 2001-10-24. This release corresponds to the version of my EOS
code that has been used, for example, in "A Large Stellar Evolution Database
for Population Synthesis Studies. I. Scaled Solar Models and Isochrones"
(Pietrinferni et al. 2004 ApJ 612, 168).
-
2004-09-09: Established the freeeos-general mailing
list. This is the list you
should subscribe to if you want to follow what is happening with FreeEOS!
-
2004-09-08: FreeEOS-1.0.0
released. This is a snapshot of my stable code base as of 2000-07-06
which was previously released as
ftp://astroftp.phys.uvic.ca/pub/irwin/eos/code/eos_demo_fortran.tar.gz. This
release corresponds to the version of my EOS code that has been used, for
example, in "The Initial Helium Content of Galactic Globular Cluster Stars
from the R-Parameter: Comparison with the Cosmic Microwave Background
Constraint" (Cassisi, Salaris, and Irwin: 2003, ApJ 588, 862).
-
2004-09-03: Registered FreeEOS project at SourceForge
