[Scip] New versions of SCIP, SoPlex, and ZIMPL released

[Timo Berthold]

Dear all,

Version 1.2 of the ZIB Optimization Suite has been released.
It comprises the new versions SCIP 1.2, Soplex 1.4.2, and ZIMPL 3.0.0.
It provides many new features -- including a first support for nonconvex 
MINLP --, performance improvements, and bug fixes.
It can be obtained via http://zibopt.zib.de, for detailed information see the 
SCIP web site http://scip.zib.de.

Best regards,
the SCIP team


The release notes of the individual software packages are:

NOTES FOR SCIP RELEASE 1.2

Features
========

- Preliminary support of non-convex MIQCPs: Constraint handler for
  quadratic constraints, NLP heuristic, and Ipopt interface

- Improved support of branch-and-price: SCIP now supports lazy bounds, early 
  branching/incomplete pricing, and primal heuristics during pricing loop

- Constraint handler for indicator constraints and parsing them from *.lp
  and *.zpl files

- Heuristics which are applied before root LP

- Black-box lexicographic dual simplex algorithm

- Copy constructors and i/o functionality for constraints

Interfaces
==========

- First version of LP interfaces to Gurobi and QSopt

- Major performance improvements in LP interfaces to Clp, Mosek, and SoPlex

- Reader for Flatzinc and GAMS models

- Adjusted interface to Zimpl version 3.0.0

- On http://code.google.com/p/python-zibopt/source/checkout you find a beta 
  version of a python interface to SCIP implemented by Ryan J. O'Neil.
  
Performance Improvements and Bug Fixes
======================================

- Enhanced MCF cuts: stable version, used by default

- Improved hybrid branching

- Increased numerical stability for Big M formulations

- Several improvements in presolving

- Many bug fixes


NOTES FOR SOPLEX RELEASE 1.4.2

What's new
----------
 - Improved memory efficiency and reading of large LP files.
 - Improved detection of cycling.
 - When using the callable library: copy constructors and assignment
   operators are now available for all major classes.
 - Several bugfixes and improvements in numerical stability.


NOTES FOR ZIMPL RELEASE 3.0.0

 - support of indicator constraints
 - support of quadratic constraints
 - constraints can now be marked as checkonly
 - bug fixes