Provides a 'PROJ' <https://proj.org> C API that can be used to write high-performance C and C++ coordinate transformation operations using R as an interface. This package contains an internal version of the 'PROJ' library to guarantee the best possible consistency on multiple platforms, and to provide a means by which 'PROJ' can be used on platforms where it may be impractical or impossible to install a binary version of the library.
Useful links: