cpc.geogrids.definition Module

Defines a GeoGrid object. Grid objects store certain properties of a gridded dataset (lat/lon grid corners, resolution, etc.), and can simplify defining a grid when calling utilities such as interpolation routines, plotting, etc.

Data

• builtin_geogrids = {'2.5deg-global': {'...

Functions

list_builtin_geogrids()

cpc.geogrids.definition.Geogrid Objects

__init__(self, name=None, ll_corner=None, ur_corner=None, res=None, type=’latlon’)

__repr__(self)

data_fits(self, data)

Determines if the specified data fits this Geogrid

Parameters

• data - array_like - data to verify

Returns

• boolean - whether the data fits this Geogrid

Exceptions

• GeogridError - raised if data is not a valid NumPy array

Examples

>>> import numpy as np
>>> from cpc.geogrids import Geogrid
>>> grid = Geogrid('1deg-global')
>>> data = np.random.random((grid.num_y, grid.num_x))
>>> data.shape
(181, 360)
>>> grid.data_fits(data)
True
>>> data = np.random.random((grid.num_y + 1, grid.num_x + 1))
>>> data.shape
(182, 361)
>>> grid.data_fits(data)
False

latlon_to_1d_index(self, latlons)

Returns the 1-dimensional index of the grid point, from this Geogrid, that is located at the specified lat/lon position

For example, you may have a 1-dimensional data array on a 1deg-global Geogrid, and you want to know the index corresponding to 50 deg lat, -80 deg lon.

Parameters

• latlons - tuple of floats or list of tuples of floats - lat/lon of grid point(s)

Returns

• int or None - array index containing the given gridpoint(s) index(es), or -1 if no gridpoint matches the given lat/lon value

Examples

Get the index of a 1deg-global grid at 50 deg lat, -80 deg lon

>>> from cpc.geogrids import Geogrid
>>> grid = Geogrid('1deg-global')
>>> grid.latlon_to_1d_index((50, -80))
[50820]

Get the index of 1deg-global grid at several lat/lon points

>>> from cpc.geogrids import Geogrid
>>> grid = Geogrid('1deg-global')
>>> grid.latlon_to_1d_index([(0, 0), (20, 40), (50, -80)])
[90, 7350, 50820]

cpc.geogrids.definition.Grid Objects

__init__(self, name=None, ll_corner=None, ur_corner=None, res=None, type=’latlon’)

__repr__(self)

data_fits(self, data)

Determines if the specified data fits this Geogrid

Parameters

• data - array_like - data to verify

Returns

• boolean - whether the data fits this Geogrid

Exceptions

• GeogridError - raised if data is not a valid NumPy array

Examples

>>> import numpy as np
>>> from cpc.geogrids import Geogrid
>>> grid = Geogrid('1deg-global')
>>> data = np.random.random((grid.num_y, grid.num_x))
>>> data.shape
(181, 360)
>>> grid.data_fits(data)
True
>>> data = np.random.random((grid.num_y + 1, grid.num_x + 1))
>>> data.shape
(182, 361)
>>> grid.data_fits(data)
False

latlon_to_1d_index(self, latlons)

Returns the 1-dimensional index of the grid point, from this Geogrid, that is located at the specified lat/lon position

For example, you may have a 1-dimensional data array on a 1deg-global Geogrid, and you want to know the index corresponding to 50 deg lat, -80 deg lon.

Parameters

• latlons - tuple of floats or list of tuples of floats - lat/lon of grid point(s)

Returns

• int or None - array index containing the given gridpoint(s) index(es), or -1 if no gridpoint matches the given lat/lon value

Examples

Get the index of a 1deg-global grid at 50 deg lat, -80 deg lon

>>> from cpc.geogrids import Geogrid
>>> grid = Geogrid('1deg-global')
>>> grid.latlon_to_1d_index((50, -80))
[50820]

Get the index of 1deg-global grid at several lat/lon points

>>> from cpc.geogrids import Geogrid
>>> grid = Geogrid('1deg-global')
>>> grid.latlon_to_1d_index([(0, 0), (20, 40), (50, -80)])
[90, 7350, 50820]