univ_proposal: MCMC proposal function
In jameshay218/antibodyKinetics: antibodyKinetics

Proposal function for MCMC random walk, taking random steps of a given size. Random walk may be on a linear or log scale

1	univ_proposal(values, lower_bounds, upper_bounds, steps, index)

`values`	a vector of the parameters to be explored
`lower_bounds`	a vector of the low allowable bounds for the proposal
`upper_bounds`	a vector of the upper allowable bounds for the proposal
`steps`	a vector of step sizes for the proposal
`index`	numeric value for the index of the parameter to be moved from the param table and vector