NEMO Ocean Data Gallery Example

docs/iris/example_code/Oceanography/load_nemo.py

@@ -0,0 +1,59 @@
+"""
+Load a time series of data from the NEMO model
+==============================================
+
+This example demonstrates how to load multiple files containing data output by
+the NEMO model and combine them into a time series in a single cube. The
+different time dimensions in these files can prevent Iris from concatenating
+them without the intervention shown here.
+"""
+from __future__ import unicode_literals
+
+import iris
+import iris.plot as iplt
+import iris.quickplot as qplt
+import matplotlib.pyplot as plt
+from iris.util import promote_aux_coord_to_dim_coord
+
+
+def main():
+    # Load the three files of sample NEMO data.
+    fname = iris.sample_data_path('NEMO/nemo_1m_*.nc')
+    cubes = iris.load(fname)
+
+    # Some attributes are unique to each file and must be blanked
+    # to allow concatenation.
+    differing_attrs = ['file_name', 'name', 'timeStamp', 'TimeStamp']
+    for cube in cubes:
+        for attribute in differing_attrs:
+            cube.attributes[attribute] = ''
+
+    # The cubes still cannot be concatenated because their time dimension is
+    # time_counter rather than time. time needs to be promoted to allow
+    # concatenation.
+    for cube in cubes:
+        promote_aux_coord_to_dim_coord(cube, 'time')
+
+    # The cubes can now be concatenated into a single time series.
+    cube = cubes.concatenate_cube()
+
+    # Generate a time series plot of a single point
+    plt.figure()
+    y_point_index = 100
+    x_point_index = 100
+    qplt.plot(cube[:, y_point_index, x_point_index], 'o-')
+
+    # Include the point's position in the plot's title
+    lat_point = cube.coord('latitude').points[y_point_index, x_point_index]
+    lat_string = '{:.3f}\u00B0 {}'.format(abs(lat_point),
+                                          'N' if lat_point > 0. else 'S')
+    lon_point = cube.coord('longitude').points[y_point_index, x_point_index]
+    lon_string = '{:.3f}\u00B0 {}'.format(abs(lon_point),
+                                          'E' if lon_point > 0. else 'W')
+    plt.title('{} at {} {}'.format(cube.long_name.capitalize(),
+                                   lat_string, lon_string))
+    iplt.show()
+
+
+if __name__ == '__main__':
+    main()

docs/iris/example_tests/test_load_nemo.py

@@ -0,0 +1,41 @@
+# (C) British Crown Copyright 2019, Met Office
+#
+# This file is part of Iris.
+#
+# Iris is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Iris is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Iris.  If not, see <http://www.gnu.org/licenses/>.
+
+from __future__ import (absolute_import, division, print_function)
+from six.moves import (filter, input, map, range, zip)  # noqa
+
+# Import Iris tests first so that some things can be initialised before
+# importing anything else.
+import iris.tests as tests
+
+from .extest_util import (add_examples_to_path,
+                          show_replaced_by_check_graphic,
+                          fail_any_deprecation_warnings)
+
+
+class TestLoadNemo(tests.GraphicsTest):
+    """Test the load_nemo example code."""
+    def test_load_nemo(self):
+        with fail_any_deprecation_warnings():
+            with add_examples_to_path():
+                import load_nemo
+            with show_replaced_by_check_graphic(self):
+                load_nemo.main()
+
+
+if __name__ == '__main__':
+    tests.main()

docs/iris/src/whatsnew/contributions_2.3.0/docchange_2019-Sep-13_nemo_gallery_example.txt

@@ -0,0 +1 @@
+Added a gallery example showing how to concatenate NEMO ocean model data.

lib/iris/tests/results/imagerepo.json

@@ -83,6 +83,9 @@
         "https://scitools.github.io/test-iris-imagehash/images/v4/eae942146540b869961f8de694589da69543cc9af1014afbc3fd596b84fe19a7.png",
         "https://scitools.github.io/test-iris-imagehash/images/v4/eafd9e12a5a061e9925ec716de489e9685078ec981b229e70ddb79219cc3768d.png"
     ],
+    "example_tests.test_load_nemo.TestLoadNemo.test_load_nemo.0": [
+        "https://scitools.github.io/test-iris-imagehash/images/v4/a3ff34e87f0049496d17c4d9c04fc225d256971392d39f1696df0f16cec00f36.png"
+    ],
     "example_tests.test_orca_projection.TestOrcaProjection.test_orca_projection.0": [
         "https://scitools.github.io/test-iris-imagehash/images/v4/fb11731a94cea4ee64b35e91d1d2304e9e5ac7397b20e1fe12852487e666ce46.png",
         "https://scitools.github.io/test-iris-imagehash/images/v4/bb11721a87cce5e4cce79e81d19b3b5e1e1cd3783168e07835853485e65e2e1e.png"