  We describe an algorithm to find the virtual cohomological dimension of the
automorphism group of a right-angled Artin group. The algorithm works in the
relative setting; in particular it also applies to untwisted automorphism
groups and basis-conjugating automorphism groups. The main new tool is the
construction of free abelian subgroups of certain Fouxe-Rabinovitch groups of
rank equal to their virtual cohomological dimension, generalizing a result of
Meucci in the setting of free groups.
