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.. testsetup::
from pyresample.geometry import AreaDefinition
area_id = 'ease_sh'
description = 'Antarctic EASE grid'
proj_id = 'ease_sh'
projection = {'proj': 'laea', 'lat_0': -90, 'lon_0': 0, 'a': 6371228.0, 'units': 'm'}
width = 425
height = 425
area_extent = (-5326849.0625, -5326849.0625, 5326849.0625, 5326849.0625)
area_def = AreaDefinition(area_id, description, proj_id, projection,
width, height, area_extent)
import numpy as np
lons = np.zeros(1000)
lats = np.arange(-80, -90, -0.01)
tb37v = np.arange(1000)
from pyresample import SwathDefinition
swath_def = SwathDefinition(lons, lats)
if plt is not None:
import matplotlib
matplotlib.use('agg')
The Plate Carree projection
+++++++++++++++++++++++++++
The Plate Carree projection (regular lon/lat grid) is named **eqc** in
Proj.4. Pyresample uses the Proj.4 naming.
Assuming the file **areas.yaml** has the following area definition:
.. code-block:: yaml
pc_world:
description: Plate Carree world map
projection:
proj: eqc
ellps: WGS84
shape:
height: 480
width: 640
area_extent:
lower_left_xy: [-20037508.34, -10018754.17]
upper_right_xy: [20037508.34, 10018754.17]
**Example usage:**
.. testsetup::
from pyresample.area_config import load_area_from_string
area_def = load_area_from_string("""
pc_world:
description: Plate Carree world map
projection:
proj: eqc
ellps: WGS84
shape:
height: 480
width: 640
area_extent:
lower_left_xy: [-20037508.34, -10018754.17]
upper_right_xy: [20037508.34, 10018754.17]
""", "pc_world")
.. doctest::
:skipif: plt is None or cartopy is None
>>> import matplotlib.pyplot as plt
>>> from pyresample import load_area, save_quicklook
>>> from pyresample.kd_tree import resample_nearest
>>> area_def = load_area('areas.yaml', 'pc_world') # doctest: +SKIP
>>> result = resample_nearest(swath_def, tb37v, area_def, radius_of_influence=20000, fill_value=None)
>>> save_quicklook('tb37v_pc.png', area_def, result, num_meridians=None, num_parallels=None, label='Tb 37v (K)') # doctest: +SKIP
Assuming **lons**, **lats** and **tb37v** are initialized with real data (like
above we use AMSR-2 data in this example) the result might look something like
this:
.. image:: /_static/images/tb37v_pc.png
The Globe projections
+++++++++++++++++++++
From v0.7.12 pyresample can use the geos, ortho and nsper projections with
Basemap. Starting with v1.9.0 quicklooks are now generated with Cartopy_ which
should also work with these projections. Again assuming the area-config file
**areas.yaml** has the following definition for an ortho projection area:
.. code-block:: bash
ortho:
description: Ortho globe
projection:
proj: ortho
lon_0: 40.
lat_0: -40.
a: 6370997.0
shape:
height: 480
width: 640
area_extent:
lower_left_xy: [-10000000, -10000000]
upper_right_xy: [10000000, 10000000]
**Example usage:**
.. testsetup::
from pyresample.area_config import load_area_from_string
area_def = load_area_from_string("""
ortho:
description: Ortho globe
projection:
proj: ortho
lon_0: 40.
lat_0: -40.
a: 6370997.0
shape:
height: 480
width: 640
area_extent:
lower_left_xy: [-10000000, -10000000]
upper_right_xy: [10000000, 10000000]
""", "ortho")
.. doctest::
:skipif: plt is None or cartopy is None
>>> from pyresample import load_area, save_quicklook, SwathDefinition
>>> from pyresample.kd_tree import resample_nearest
>>> from pyresample import load_area
>>> area_def = load_area('areas.yaml', 'ortho') # doctest: +SKIP
>>> swath_def = SwathDefinition(lons, lats)
>>> result = resample_nearest(swath_def, tb37v, area_def, radius_of_influence=20000, fill_value=None)
>>> save_quicklook('tb37v_ortho.png', area_def, result, num_meridians=None, num_parallels=None, label='Tb 37v (K)') # doctest: +SKIP
Assuming **lons**, **lats** and **tb37v** are initialized with real data, like
in the above examples, the result might look something like this:
.. image:: /_static/images/tb37v_ortho.png
.. _Cartopy: http://scitools.org.uk/cartopy/
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