Reordering shows no effect.

[hoemich]

The BDDFactory.reorder(...) seems to have no effect.

bddLib.bddFactory.reorderVerbose(3);
bddLib.bddFactory.reorder(...);
System.out.println(bddLib.bddFactory.reorderstats);

shows some activity, but the variable ordering does not change.
At first I thought, it might be, because my variable ordering is already pretty good, yet changing the variable ordering manually (using setVarOrder()) to a new random variable ordering often reduces the size by 100 - 300%

Is there anything to know about the variable ordering?
Is it not (yet) implemented?
Is it buggy?

What more detail do you need?

[dhendriks]

To be honest, I don't know. This GitHub repo is a fork of the original JavaBDD from SourceForge, so I didn't write the library. I only use JavaBDD in the Eclipse ESCET project. There, we don't let JavaBDD determine the variable order, but we have algorithms of our own to do so.

[hoemich]

This makes sense. Apparently, with the original JavaBDD, I have the same issues. Do you predetermine the order prior to the BDD-creation, or do you actively reorder variables, as you build the BDD/after building the BDD?

[dhendriks]

I use a predetermined order, no reordering once BDDs are created.