[Coin-discuss] Cbc questions

[Brady Hunsaker]

I'm doing some work that includes examining the tree created by CBC.

John and Robin, I expect that the two of you are most likely able to
answer my questions.

First, one of the data points that I am looking at is the sum of the
infeasibilities at a subproblem.  My concern is that the value returned
by CbcSimpleIntegerDynamicPseudoCost::infeasibility (in
CbcBranchDynamic.cpp) does not return a value between 0 and 0.5, as the
comments seem to suggest.

Is this intentional?


Second, in CbcModel.cpp, around line 1060 there is a comment that says
"set node number correctly".  The accompanying call to setNodeNumber
actual changes the node number, however, and the increment of
nodeNumber2_ a few lines later also seems to be wrong.

By commenting both of these out I get a consistent node numbering.  Is
that correct?  Admittedly, CBC keeps track of nodes in a different way
then I usually think about, since it doesn't create a node until it is
processed (and only if it will have children).  It may be that someone
added those two lines while struggling as I did with this issue.

Could you clarify?

Thanks,
Brady




-- 
Brady Hunsaker
Assistant Professor
Industrial Engineering
University of Pittsburgh
http://www.engr.pitt.edu/hunsaker/