Packages required but not available: 'rgeos', 'rgdal', 'maptools'

See section ‘The DESCRIPTION file’ in the ‘Writing R Extensions’
manual.
Packages required but not available: 'rgeos', 'rgdal', 'maptools'

See section ‘The DESCRIPTION file’ in the ‘Writing R Extensions’
manual.
Namespaces in Imports field not imported from:
  ‘maptools’ ‘rgdal’ ‘rgeos’
  All declared Imports should be used.