xptr_eval

This function is used in <code>plot.itp</code> to plot a function and
the root estimated by <code>itp</code>.

Implements the Interpolate, Truncate, Project (ITP) root-finding
algorithm developed by Oliveira and Takahashi (2021) <doi:10.1145/3423597>.
The user provides the function, from the real numbers to the real numbers,
and an interval with the property that the values of the function at its
endpoints have different signs. If the function is continuous over this
interval then the ITP method estimates the value at which the function is
equal to zero. If the function is discontinuous then a point of
discontinuity at which the function changes sign may be found.
The function can be supplied using either an R function or an external
pointer to a C++ function. Tuning parameters of the ITP algorithm can be
set by the user. Default values are set based on arguments in Oliveira and
Takahashi (2021).

Paul Northrop

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

xptr_eval function

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

Arguments

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

<dl>

<dt>x</dt>
<dd>The main argument of the function.</dd>


<dt>pars</dt>
<dd>A list of additional arguments to the function. This may be an
empty list.</dd>


<dt>xpsexp</dt>
<dd>An external pointer to a C++ function.</dd>

</dl>

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

Description

Usage

Value

Arguments

Details

See Also

Examples