This function provides an example of a way in which a user can specify
their own prior density to rpost_rcpp.
More specifically, a function like this (the user will need to create
an edited version tailored to their own C++ function(s)) can be used to
generate an external pointer to a compiled C++ function that evaluates
the log-prior density. Please see the vignette
"Faster simulation using revdbayes" for more information.
create_prior_xptr(fstr)A string indicating the C++ function required.
An external pointer.
Suppose that the user's C++ functions are in a file called "user_fns.cpp".
These functions must be compiled and made available to R before the
pointer is created. This can be achieved using the function
sourceCpp in the Rcpp package
or using RStudio's Source button on the editor toolbar.
For details see the examples in the documentation of the functions
rpost_rcpp and set_prior,
the vignette "Faster simulation using revdbayes"
and the vignette "Rusting Faster: Simulation using Rcpp" in the package
rust.
set_prior to specify a prior distribution using
an external pointer returned by create_prior_xptr and for
details of in-built named prior distributions.
The examples in the documentation of rpost_rcpp.
ptr_gp_flat <- create_prior_xptr("gp_flat")
prior_cfn <- set_prior(prior = ptr_gp_flat, model = "gp", min_xi = -1)
ptr_gev_flat <- create_prior_xptr("gev_flat")
prior_cfn <- set_prior(prior = ptr_gev_flat, model = "gev", min_xi = -1,
max_xi = Inf)
mat <- diag(c(10000, 10000, 100))
ptr_gev_norm <- create_prior_xptr("gev_norm")
pn_u <- set_prior(prior = ptr_gev_norm, model = "gev", mean = c(0,0,0),
icov = solve(mat))