# Drawings

I use these grids to construct smooth approximations to bivariate angular probability densities (of interest in protein bioinformatics) and to specify semiparametric priors on bivariate angular density spaces. The grid on the Torus illustrates the proper angular wrapping behavior of planar grid. I drew them in Mathematica.

Code and variants below.

where $R$ is a side chain called the $R$-group. There are 20 different amino acids found in proteins, each characterized by its $R$-group.