Describe the bug
Hi,
I use the the observation function ecole.observation.StrongBranchingScores to extract strong branching scores of candidate variables in an application. I collect scores for only variables with a fractional solution, i.e. no pseudo candidates. I see that some candidates get a score of -1e+20. According to the SCIP source code branch_vanillafullstrong.c, all candidate scores are initialized at this value and later obtain a valid score after strong branching. By definition, a branching score should be nonnegative, so I am confused as to why this happens. If this is the result of an LP error during strong branching computation, could you suggest a method to debug this?
Thank you.
Setting
- OS: Linux
- Python version: 3.9.12
- Ecole version: 0.7.3
- SCIP version: 7.0.3
To Reproduce
Expected behavior
I would expect all strong branching scores to be >= 0 and I would expect a message if no scores could be extracted for a variable due to some error.
Additional context
Describe the bug
Hi,
I use the the observation function ecole.observation.StrongBranchingScores to extract strong branching scores of candidate variables in an application. I collect scores for only variables with a fractional solution, i.e. no pseudo candidates. I see that some candidates get a score of -1e+20. According to the SCIP source code branch_vanillafullstrong.c, all candidate scores are initialized at this value and later obtain a valid score after strong branching. By definition, a branching score should be nonnegative, so I am confused as to why this happens. If this is the result of an LP error during strong branching computation, could you suggest a method to debug this?
Thank you.
Setting
To Reproduce
Expected behavior
I would expect all strong branching scores to be >= 0 and I would expect a message if no scores could be extracted for a variable due to some error.
Additional context