Package

r-rgeos

Description

Interface to Geometry Engine - Open Source ('GEOS'). Interface to
Geometry Engine - Open Source ('GEOS') using the C 'API' for topology
operations on geometries. The 'GEOS' library is external to the package,
and, when installing the package from source, must be correctly
installed first. Windows and Mac Intel OS X binaries are provided on
'CRAN'. ('rgeos' >= 0.5-1): Up to and including 'GEOS' 3.7.1,
topological operations succeeded with some invalid geometries for which
the same operations fail from and including 'GEOS' 3.7.2. The
'checkValidity=' argument defaults and structure have been changed, from
default FALSE to integer default '0L' for 'GEOS' < 3.7.2 (no check),
'1L' 'GEOS' >= 3.7.2 (check and warn). A value of '2L' is also provided
that may be used, assigned globally using 'set_RGEOS_CheckValidity(2L)',
or locally using the 'checkValidity=2L' argument, to attempt zero-width
buffer repair if invalid geometries are found. The previous default
(FALSE, now '0L') is fastest and used for 'GEOS' < 3.7.2, but will not
warn users of possible problems before the failure of topological
operations that previously succeeded. From 'GEOS' 3.8.0, repair of
geometries may also be attempted using 'gMakeValid()', which may,
however, return a collection of geometries of different types.

Note