  We review a method, suggested many years ago, to numerically measure the
relative amplitudes of the true Yang-Mills vacuum wavefunctional in a finite
set of lattice-regulated field configurations. The technique is applied in 2+1
dimensions to sets of abelian plane wave configurations of varying amplitude
and wavelength, and sets of non-abelian constant configurations. The results
are compared to the predictions of several proposed versions of the Yang-Mills
vacuum wavefunctional that have appeared in the literature. These include (i) a
suggestion in temporal gauge due to Greensite and Olejnik; (ii) the "new
variables" wavefunction put forward by Karabali, Kim, and Nair; (iii) a hybrid
proposal combining features of the temporal gauge and new variables
wavefunctionals; and (iv) Coulomb gauge wavefunctionals developed by Reinhardt
and co-workers, and by Szczepaniak and co-workers. We find that wavefunctionals
which simplify to a "dimensional reduction" form at large scales, i.e. which
have the form of a probability distribution for two-dimensional lattice gauge
theory, when evaluated on long-wavelength configurations, have the optimal
agreement with the data.
