xptr_eval: Call a C++ function using an external pointer

In itp: The Interpolate, Truncate, Project (ITP) Root-Finding Algorithm

Call a C++ function using an external pointer

Description

This function is used in plot.itp to plot a function and the root estimated by itp.

Usage

xptr_eval(x, pars, xpsexp)

Arguments

x	The main argument of the function.
pars	A list of additional arguments to the function. This may be an empty list.
xpsexp	An external pointer to a C++ function.

Details

See the Passing user-supplied C++ functions article in the Rcpp Gallery for information.

Value

A numeric scalar: the value of the C++ function evaluated at the input values x and pars.

See Also

xptr_create for creating an external pointer to a C++ function.

Examples

lambert_ptr <- xptr_create("lambert")
res <- itp(lambert_ptr, c(-1, 1))

# Value at lower limit
xptr_eval(-1, list(), lambert_ptr)

# Value at upper limit
xptr_eval(1, list(), lambert_ptr)

# Value at the estimated root
xptr_eval(res$root, list(), lambert_ptr)

itp documentation built on May 29, 2024, 5:58 a.m.