mapset sets the mapping parameters.
lonmin=lonmin - minimum longitude
lonmax=lonmax - maximum longitude
latmin=latmin - minimum latitude
latmax=latmax - maximum latitude
proj=proj - ‘cyl’ for cylindrical projection. ‘npstere’ or ‘spstere’
for northern hemisphere or southern hemisphere polar stereographic
projection. Use’moll’ for the mollweide projection.
boundinglat=boundinglat - edge of the viewable latitudes in a
lon_0=0 - longitude centre of desired map domain in polar
stereographic and orthogrphic plots
lat_0=40 - latitude centre of desired map domain in orthogrphic plots
resolution=‘110m’ - the map resolution - can be one of ‘110m’,
‘50m’ or ‘10m’. ‘50m’ means 1:50,000,000 and not 50 metre.
user_mapset=user_mapset - variable to indicate whether a user call
The default map plotting projection is the cyclindrical equidistant
projection from -180 to 180 in longitude and -90 to 90 in latitude.
To change the map view in this projection to over the United Kingdom,
for example, you would use
mapset(lonmin=-6, lonmax=3, latmin=50, latmax=60)
or
mapset(-6, 3, 50, 60)
The limits are -360 to 720 in longitude so to look at the equatorial
Pacific you could use
mapset(lonmin=90, lonmax=300, latmin=-30, latmax=30)
or
mapset(lonmin=-270, lonmax=-60, latmin=-30, latmax=30)
The proj parameter accepts ‘npstere’ and ‘spstere’ for northern
hemisphere or southern hemisphere polar stereographic projections.
In addition to these the boundinglat parameter sets the edge of the
viewable latitudes and lat_0 sets the centre of desired map domain.
Additional map projections via proj are:
ortho, merc, moll, robin and lcc
These are abreviations for orthographic, mercator, mollweide, robinson
and lambert conformal projections
For Lambert Conformal Projection, lcc, plots the following extra
parameters are required.
lat_1=45 - first standard parallel
lat_2=55 - second standard parallel
width=12000000 - width of Lambert Conformal Projection, lcc
height=9000000 - height of Lambert Conformal Projection, lcc
plimits=None - plot limits [lonmin, lonmax, latmin, latmax] for lcc plot
examples of using the Lambert Conformal Projection.
Data must be continuous and contiguous and you must select the same
plot limits as your data. i.e. if you have data that is -60 to 30
in longitude then the plot limits must also be -60 to 30 in longitude.
Map settings are persistent until a new call to mapset is made. To
reset to the default map settings use mapset().