- shape
The path to a shapefile containing land polygons of the study area.
- size
The pixel size, in metres.
- spatial
Either a character string specifying the path to a spatial.csv file or a spatial data frame.
This argument is not mandatory, but can be used to perform an early check of the shape file's compatibility
with the study stations and release sites.
- coord.x, coord.y
The names of the columns containing the x and y positions of the stations
in the spatial.csv file. these coordinates MUST BE in the same coordinate system as the shape file.
- buffer
Artificially expand the map edges. Can be a single value (applied to all edges)
or four values (xmin, xmax, ymin, ymax). The unit of the buffer depends on the shape file's
coordinate system.
- type
The type of shapefile being loaded. One of "land", if the shapefile's polygons represent landmasses, or "water", if the shapefile's polygons represent water bodies.