[Scip] How to get all transformed and presolved variables?

[Martin Bergner]

Hi all,

I want to collect some statistics on my problem just after presolving
has been finished. That means that I want to explicitly work with the
presolved problem. 

I therefore implemented an empty presolver and try to do most of the
work in the scip_exitpre method. I basically want to assign some
variable data to transformed and presolved variables where I can collect
some statistics. 

When I either call SCIPgetVars or SCIPgetOrigVars followed by
SCIPgetTransformedVars, I do not get all variables. When looping over
all constraints and the variables in the constraints, I get additional
variables which have not been found by either one of the two methods
mentioned above.

After some debugging, I realized that the variables are presolved
variables, the name being t_*_bin or t_*_neg or some combination. That
somehow seems to make sense, as the two methods above only return
transformed variables but the problematic variables are not only
transformed but aggregated. 

Is it possible to have access to these variables besides looking at all
constraints and inspecting the variables for each constraint? Or
alternatively: How do I get all the variables and constraints from the
presolved problem? 

Thank you and kind regards,
Martin