Perform Hamiltonian Monte Carlo

hmc_helper(log_posterior, gradient, step_size, n_steps, init_parameters, iters)

Arguments

log_posterior

a function for the unnormalised log-posterior from parameters -> log-likelihood

gradient

the gradient of the log_posterior

step_size

the step size of the leapfrog steps

n_steps

the number of leapfrog steps

init_parameters

a named vector containing the initial parameters

iters

the number of iterations

Value

a matrix of iterations from the HMC algorithm representing draws from the posterior distribution