[RFC]: notations used in this package

[yebai]

At the moment, we are using the following notations:

• logπ - log target distribution
• ∂logπ∂θ - gradient
• prop - transitioning kernel
• θ_init - initial value for sampling states / parameters

I think this can be improved by

• ∂logπ∂θ ==> ∇logπ
• prop ==> κ (kappa) or τ (tau) - MH transitioning kernel
• θ - parameters, r - momentum
• θ_init ==> θ₀ (theta_{0}), r_init ==> r₀ (r_{0})
• z := (θ, r) - (position, momentum) pair

Any other notations missing?

[willtebbutt]

I completely agree with all of @yebai 's proposals. Couple of quick comments:

• I would prefer τ to kappa, but don't have a hugely strong feeling either way.
• By q₀, do you mean q₀ or r₀?

If the above are resolved, I'm happy 🙂

[yebai]

By q₀, do you mean q₀ or r₀?

should be r₀.

[xukai92]

Nice call! I agree we with these notations! Let's change to them.

[xukai92]

@yebai Did we have similar agreement on things like \epsilon used in Turing?

[yebai]

@yebai Did we have similar agreement on things like \epsilon used in Turing?

how about using the symbol ϵ?

[xukai92]

\epsilon is ϵ