FreeEOS / News: Recent posts

FreeEOS is a GPL-licensed software library for calculating an equation of state for conditions in stellar interiors. The latest stable version of this library source code, FreeEOS-3.3.0, has been released on 2022-06-05 some 14 (!) years after the last stable release, FreeEOS-2.2.1.

Many stellar-interior groups have chosen to adopt FreeEOS-2.2.1 to provide the EOS data they need to calculate their models since if you adopt exact OPAL abundances, it replicates OPAL results well (especially the OPAL solar results) through much of the physical conditions covered by those results. Furthermore, FreeEOS can be used to extrapolate smoothly from OPAL results for different abundances and a wider range of physical conditions than used in the OPAL calculations. Note, however, all the normal extrapolation caveats.... read more

FreeEOS is a software library for calculating an equation of state for conditions in stellar interiors. The latest stable version of this library source code, FreeEOS-2.2.1, has been released on 2008-07-08.

The new release fixes all known bugs in FreeEOS-2.2.0 and has negligible changes (see http://freeeos.sourceforge.net/2.2.1-2.1.0.png\) 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.... read more

FreeEOS is a software library for calculating an equation of state for conditions in stellar interiors. The latest stable version of this library source code, FreeEOS-2.2.0, has been released on 2007-07-24. The new release has an improved implementation of the EOS1 free-energy model which leads to systematic but negligible (http://freeeos.sf.net/2.2.0-2.1.0.png) 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 the announcement (http://freeeos.sf.net/announcement-2.2.0.html) for the details of 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.

FreeEOS is a software library for calculating an equation of state for conditions in stellar interiors. The latest stable version of this library source code, FreeEOS-2.1.0, has been released on 2007-06-17. The principal changes to the software for this version of FreeEOS are a new API and new CMake-based build system. For more details about this release, please see http://freeeos.sourceforge.net/announcement-2.1.0.html.

The cvs2svn script helped to preserve all the commit and tagged release information that was in the previous CVS repository.

FreeEOS is a software library for calculating an equation of state for conditions in stellar interiors. The latest stable version of this library source code, FreeEOS-2.0.0, has been released on 2006-01-15. The principal change to the software for this version of FreeEOS is a complete reorganization of the Newton-Raphson iteration scheme. The former scheme, which did an "outer" iteration to determine the degeneracy parameter, fl, and an "inner" iteration to determine auxiliary variables for fixed fl, has been replaced by a combined iteration to determine fl and auxiliary variables simultaneously. The new iteration scheme is significantly faster (a factor of two in some situations). For more details about this release, please see http://freeeos.sourceforge.net/announcement-2.0.0.html.

FreeEOS is a stable software library for calculating an equation of state for conditions in stellar interiors. The latest stable version of this library source code, FreeEOS-1.6.0, has been released on 2005-09-01. The principal change to the software for this version of FreeEOS is the physical constants have been upgraded from CODATA 1986 to CODATA 2002. For more details see the announcement at http://freeeos.sourceforge.net/announcement-1.6.0.html . This stable release is the one I will support from now on and also gives the most accurate benchmark against the next stable release so this is the version you want until that next stable release.

Version 1.5.0 of FreeEOS has been released. For details of this release
please consult http://freeeos.sourceforge.net/announcement-1.5.0.html .

This is the stable version of FreeEOS that I used to produce all the figures
in Paper IV and also the only version of FreeEOS that I will support until
the next stable release so this is the version that you want to use.

This release incorporates improvements to the exchange treatment underlying
FreeEOS that are detailed in Paper IV
(http://freeeos.sourceforge.net/exchange.pdf) in my series of papers
describing the FreeEOS implementation. Links to additional papers in the
series and also additional FreeEOS documentation can be found at
http://freeeos.sourceforge.net/documentation.html .