  In this work we propose a new algorithm for the computation of statistical
equilibrium quantities on a cubic lattice when both an energy and a statistical
temperature are involved. We demonstrate that the pivot algorithm used in
situations such as protein folding works well for a small range of temperatures
near the polymeric case, but it fails in other situations. The new algorithm,
using localized transformations, seems to perform well for all possible
temperature values. Having reliably approximated the values of equilibrium
energy, we also propose an efficient way to compute equilibrium entropy for all
temperature values. We apply the algorithms in the context of suction or
supercritical vortices in a tornadic flow, which are approximated by vortex
filaments on a cubic lattice. We confirm that supercritical (smooth,
"straight") vortices have the highest energy and correspond to negative
temperatures in this model. The lowest-energy configurations are folded up and
"balled up" to a great extent. The results support A. Chorin's findings that,
in the context of supercritical vortices in a tornadic flow, when such
high-energy vortices stretch, they need to fold.
