A tiny Metropolis-Hastings neural networks optimizer, inspired by micrograd.
This version is contemporary with Micropolis II.
- optim.MMH(test='Barker') implements the approximate Barker MH test of [6.3, BDH17].
- optim.MMH(test='exact') implements the exact Barker MH test of [SPCC17] (& thanks to BIDData/BIDMach for the normal-to-logistic correction distriution).