Update rates by calling rate functions via Xptr.

CALL_RATE_FCN(rates, inds, state, parameters, constants, tcovar, rate_ptr)

Arguments

rates

vector of rates to be modified

inds

logical vector of indices of rates to be modified

state

numeric vector of comaprtment counts

parameters

numeric vector of parameter values

constants

numeric vector of constants

tcovar

numeric vector of time-varying covariate values

rate_ptr

external pointer to rate function