[SCIP] Questions regarding SCIPgetLPBranchCands

[Oliver Zier]

 Hi all,


I am using SCIP as a branch and price framework and have 2 questions
during my implementation:

1. I noticed that while the current lp relaxation has some variables with
solution values e.g 8e-8, SCIP does not consider those as branching
candidates (using SCIPgetLPBranchCands). But as far as I know, the default
tolerance is 1e-9. Is this just rounding error? I am printing out current
LP relaxation solution using SCIPprintSol(scip, NULL, NULL, false).

2. I have one instance in which after I fixed one variable to 0 using
SCIPfixVar, in the LP relaxation solution after that constraint
propagration, the solution value of that variable is about 1.4e-7. I did
print out the variable after fixing it and the local bound is [0,0]. What
could be the source of error here? It also does not appear in the lpcands
set.


Thank you for your time.


Best,
Oliver