Information about ucbdata

[Ana Ramos]

Dear all,
We are trying to lead the branching variable in the B&B performed by
XPRESS.
To this end, we have found the callback function XPRS_CB_CHGBRANCH
that in
principle allows to choose the new branching var. by means of the
ucbdata
procedure.

Our question is about the parameter of this function. In principle,
the
documentation states that the first parameter is the column number of
the
variable chosen to branch. However, in our problem there are above
2000
binary variables (declared) in the first columns but the program
returns a
error message when we try to fix a variable index larger than 800.

Could you explain us the exact meaning of the parameter of this
ucbdata
procedure?

Our second question is about the information that defines a node in
the
branching tree. How can we recover the branching variables that define
each
node of the branching tree?

Thanks.