https://github.com/eddelbuettel/rcppnloptexample

Rcpp Example for accessing NLopt
https://github.com/eddelbuettel/rcppnloptexample

Last synced: 10 months ago
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Rcpp Example for accessing NLopt

• Host: GitHub
• URL: https://github.com/eddelbuettel/rcppnloptexample
• Owner: eddelbuettel
• Created: 2018-10-01T11:37:28.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2025-05-26T13:35:22.000Z (about 1 year ago)
• Last Synced: 2025-07-27T13:39:21.408Z (11 months ago)
• Language: C++
• Size: 23.4 KB
• Stars: 14
• Watchers: 6
• Forks: 3
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: ChangeLog

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README

          
## RcppNLoptExample: Rcpp example of using [NLopt](https://nlopt.readthedocs.io/en/latest/) via [nloptr](https://github.com/astamm/nloptr)

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### About

Starting with its 1.2.0 release, the [nloptr](https://github.com/astamm/nloptr) package by [Jelmer

Ypma](https://github.com/jyypma) now exports its C symbols in a way that makes it accessible to

other R packages _without linking_ easing the installation across operating systems.

This package illustrates this with an example drawn from the [NLopt

tutorial](https://nlopt.readthedocs.io/en/latest/NLopt_Tutorial/).

### Example

See the (currently single) file

[src/nlopt.cpp](https://github.com/eddelbuettel/rcppnloptexample/blob/master/src/nlopt.cpp).

### How / Why ?

R uses C interfaces. These C interfaces can be exported _between packages_.  So when the

usual `library(nloptr)` happens, we now _also_ get a number of C functions registered.

And those are enough to run optimization from C++ as we simply _rely on the C interface

provided_. Look careful at the example code: the objective function and the constraint

functions are C functions, and the body of our example invokes C functions from

[NLopt](https://nlopt.readthedocs.io/en/latest/). _This just works_.

On the other hand, if we tried to use the [NLopt](https://nlopt.readthedocs.io/en/latest/)

C++ interface _which brings with it someinterface code_ we would require linking to that

code (which R cannot easily export across packages using its C interface). So C it is.

### See Also

This repo builds on, extends, and simplifies an earlier [repo by Julien

Chiquet](https://github.com/jchiquet/RcppArmadilloNLoptExample) to which I contributed a core part

of this setup.

### Author

Dirk Eddelbuettel

### License

GPL (>= 2)