[Coin-lpsolver] getPrimalRay()

[Anureet Saxena]

hi,

I am trying to use OsiClpSolverInterface::getPrimalRay(const int) to extract
extreme rays of a certain unbounded linear program. I have two questions and
would  really appreciate if someone could help me with these: 

1. The primal rays returned by getPrimalRay() are double arrays with very large
numbers. Even for a very simple linear program with 2 variables and one
constraint the extreme ray seems to have numbers of the order of 10^8. A very
simple example and code to illustrate this is available at:

http://www.andrew.cmu.edu/user/anureets/tmp/primalRay.tgz

As I understand, OsiClp is performing some kind of persolve analysis which
leads to this behaviour. 

a. Is it possibe to instruct the presolver to return "neat" extreme rays?
b. Is it possible to turn off this presolve analysis? 

2. The argument to getPrimalRays(const int) seems redundant since the code
anyway returns only one extreme ray (This is also the case with OsiCpx).

regards,
anureet




Anureet Saxena
 anureet at cmu.edu
 anureet at yahoo.com
 
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