The ggpolar() function uses ggplot2::coord_map(), which depends on the mapproj package.
However, coord_map() is superseded in ggplot2 which is why the dependency on mapproj seems to have been removed by the ggplot2 authors in the current version.
Therefore, after installing grfxtools from scratch (i.e. starting with an empty R user package library), this will cause ggpolar() to exit with the error that the mapproj package is missing.
The
ggpolar()function usesggplot2::coord_map(), which depends on themapprojpackage.However,
coord_map()is superseded inggplot2which is why the dependency onmapprojseems to have been removed by theggplot2authors in the current version.Therefore, after installing
grfxtoolsfrom scratch (i.e. starting with an empty R user package library), this will causeggpolar()to exit with the error that themapprojpackage is missing.