  A methodology for computing expansion basis functions using discrete harmonic
modes is presented. The discrete harmonic modes are determined grain-by-grain
for virtual polycrystals for which finite element meshes are available. The
expansion weights associated with representing field variables over grain
domains are determined by exploiting the orthogonality of the harmonic modes.
The methodology is demonstrated with the representation of the axial stress
distributions during tensile loading of a polycrystalline sample. An open
source code, MechMonics, is available to researchers wishing to use the
methodology to analyze data.
