pywgrib2_xr.grid_fromstring¶

pywgrib2_xr.grid_fromstring(string, winds='grid', globe=None)[source]¶

Factory method to create projection from wgrib2 style string.

Parameters

string (str) –
Grid description in wgrib2 style:
- latitude longitude : ‘latlon lon0:nlon:dlon lat0:nlat:dlat’, where
  - lon0, lat0 : degrees of lat/lon for 1st grid point.
  - nlon : number of longitudes.
  - nlat : number of latitudes.
  - dlon : grid cell size in degrees of longitude.
  - dlat : grid cell size in degrees of latitude.
- rotated latitude longitude : ‘rot-ll:sp_lon:sp_lat:sp_rot lon0:nlon:dlon lat0:nlat:dlat’, where
  - sp_lon : longitude of the South pole (for rotation)
  - sp_lat : latitude of the South pole (for rotation)
  - sp_rot : angle of rotation
  - lon0, lat0 : degrees of lat/lon for 1st grid point.
  - nlon : number of longitudes.
  - nlat : number of latitudes.
  - dlon : grid cell size in degrees of longitude.
  - dlat : grid cell size in degrees of latitude.
- Mercator : ‘mercator:lad lon0:nx:dx:lonn lat0:ny:dy:latn’, where
  - lad : latitude (degrees) where dx and dy are specified.
  - lat0, lon0 : degrees of lat/lon for 1st grid point.
  - latn, lonn : degrees of lat/lon for last grid point.
  - nx : number of grid points in X direction.
  - ny : number of grid points in Y direction.
  - dx : grid cell distance in meters in x direction at lad.
  - dy : grid cell distance in meters in y direction at lad.
- north polar stereographic: ‘nps:lov:lad lon0:nx:dx lat0:ny:dy’
- south polar stereographic: ‘sps:lov:lad lon0:nx:dx lat0:ny:dy’
  - lov : longitude (degrees) where y axis is parallel to meridian.
  - lad : latitude (degrees) where dx and dy are specified. lad must be 60 (nps) or -60 (sps) (library limitation).
  - lat0, lon0 : degrees of lat/lon for 1st grid point.
  - nx : number of grid points in X direction.
  - ny : number of grid points in Y direction.
  - dx : grid cell distance meters in x direction at lad.
  - dy : grid cell distance meters in y direction at lad.
- Lambert conformal : ‘lambert:lov:latin1:latin2:lad lon0:nx:dx lat0:ny:dy’
  - lov : longitude (degrees) where y axis is parallel to meridian
  - latin1 : first latitude from pole which cuts the secant cone
  - latin2 : second latitude from pole which cuts the secant cone
  - lad : latitude (degrees) where dx and dy are specified
  - lat0, lon0 : degrees of lat/lon for first grid point
  - nx : number of grid points in X direction
  - ny : number of grid points in Y direction
  - dx : grid cell size in meters in x direction
  - dy : grid cell size in meters in y direction
- global Gaussian: ‘gaussian lon0:nx:dlon lat0:ny’
  
  lat0, lon0 : degrees of lat/lon for 1st grid point (lon1 = -lon0, lat1 = lat0 + (nx-1)*dlon)
  
  nx : number of grid points in X direction.
  
  ny : number of grid points in Y direction. ny must be even.
  
  dlon : degrees of longitude between adjacent grid points.
winds ({'grid', 'earth'}) – Vector orientation. Default is ‘grid’.
globe (dict, optional) – Mapping: code -> int, ‘shape’ -> str, ‘earth_radius’ -> float, ‘semi_major_axis’ -> float, ‘semi_minor_axis’ -> float Default is current NCEP choice: Earth assumed spherical with radius = 6,371,229.0 m.

Returns

Projection specific class instance.

Return type

Grid