William E. Hart's Blog: The Pyomo Book is Coming Soon

William E. Hart's Blog: The Pyomo Book is Coming Soon: The Python Optimization Modeling Objects (Pyomo) package is an open source tool for modeling optimization applications in Python. Pyomo can ...

Coopr 3.1 Release

It is pleased to announce the release of Coopr 3.1 (3.1.5325). Coopr
is a collection of Python software packages that supports a diverse
set of optimization capabilities for formulating and analyzing
optimization models.

The following are highlights of this release:

- Solvers
   * Interfaces for !OpenOpt solvers
   * Many solver interface improvements
   * A solver checker to validate solver interfaces
   * Improved support for SOS constraints (cplex, gurobi)
   * PH supports nonlinear models
   * PH-specific solver servers

- Modeling
   * Comprehensive rework of blocks and connectors for modular modeling
   * New !VarList component
   * Added comprehensive support for set expressions

- Usability enhancements
   * New 'coopr' command has subcommands that consolidate Coopr scripting
   * Added support to connect to databases with ODBC
   * Made JSON the default results format

- Other
   * Efficiency improvements in model generation, memory, runtime, etc.
   * Preliminary support for black-box applications
   * Deprecated modeling syntax in Coopr 3.0 is no longer legal

See https://software.sandia.gov/trac/coopr/wiki/GettingStarted for
instructions for getting started with Coopr.  Installers are available
for MS Windows and Unix operating systems to simplify the installation
of Coopr packages along with the third-party Python packages that they
depend on.  These installers can also automatically install extension
packages from Coin Bazaar.

Enjoy!

Coopr 3.0 Release

We are pleased to announce the release of Coopr 3.0 (3.0.4362). Coopr is a collection of Python software packages that supports a diverse set of optimization capabilities for formulating and analyzing optimization models.

The following are highlights of this release:

- Solvers
  * More sophisticated logic for solver factory to find ASL and OS solvers
  * Various solver interface improvements
  * New Solver results object for efficient representation of variable values
  * New support for asynchronous progressive hedging

- Modeling
  * Changes in rule semantics to limit rule return values
  * Changes in the expected order of rule arguments
  * Constant sums or products can now be used as constraint bounds
  * Added full support for the ConstraintList modeling component.

- Usability enhancements
  * More explicit output from runph and runef commands
  * Added support in runef to write the extensive form in NL format
  * Add controls for garbage collection in PH

- Other
  * Efficiency improvements in generation of NL and LP files.
  * Significant efficiency improvements in parsing of Pyomo Data Files.
  * More robust MS Windows installer (does not use virtual python
  * environment)

Note that this is a major release of Coopr that changes the expected formulation of Coopr models.  See the Coopr blog for further details about deprecated functionality, which will be disabled in future releases.

See https://software.sandia.gov/trac/coopr/wiki/GettingStarted for instructions for getting started with Coopr.  Installers are available for MS Windows and Unix operating systems to simplify the installation of Coopr packages along with the third-party Python packages that they depend on.  These installers can also automatically install extension packages from Coin Bazaar.

Enjoy!

 - Coopr Developer Team
 - coopr-developers@googlecode.com
 - https://software.sandia.gov/trac/coopr/wiki/Documentation/Developers

Coopr 2.5 Release announcement

Hart, William E is pleased to announce the release of Coopr 2.5 (2.5.3890). Coopr is a collection of Python software packages that supports a diverse set of optimization capabilities for formulating and analyzing optimization models.

The following are highlights of this release:

- Solvers
   * MIP solver interface updates to use appropriate objective names
   * Added support for suffixes in GUROBI solver interface
   * Improved diagnostic analysis of PH solver for the extensive form

- Usability enhancements
   * Improved robustness of coopr_install
   * Fixed Coopr installation problem when using easy_install
   * Added a script to launch the CooprAge GUI.
   * LP files now are written with the true objective name
   * Rework of pyomo command line to create a concise output
   * Many efficiency improvements during model generation!
   * Many improvements to diagnostic output and error handling
   * Expressions like "model.p > 1" can now be used within generation rules

- Modeling
   * Added support for generalized disjunctive programs (in coopr.gdp)
   * Constraints can now be specified in "compound" form:  lb <= expr <= ub
   * Significant robustness enhancements for model expressions
   * Improved error handling for constraint generation

- Other
   * Python 2.5 is deprecated due to performance issues
   * Python versions 2.6 and 2.7 are supported
   * New MS Windows installer is now available


See https://software.sandia.gov/trac/coopr/wiki/GettingStarted for instructions for getting started with Coopr.  Installers are available for MS Windows and Unix operating systems to simplify the installation of Coopr packages along with the third-party Python packages that they depend on.  These installers can also automatically install extension packages from Coin Bazaar.