.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "examples/plot-kgari-transect.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code. .. rst-class:: sphx-glr-example-title .. _sphx_glr_examples_plot-kgari-transect.py: ==================== K'gari transect plot ==================== .. GENERATED FROM PYTHON SOURCE LINES 6-28 .. code-block:: Python import shapely import matplotlib.pyplot as plt from matplotlib import gridspec from matplotlib.colors import LogNorm, PowerNorm import emsarray from emsarray import plot, transect, utils from emsarray.operations import depth dataset_url = 'https://thredds.nci.org.au/thredds/dodsC/fx3/gbr4_H4p0_ABARRAr2_OBRAN2020_FG2Gv3_Dhnd/gbr4_simple_2022-10-01.nc' # dataset_url = '~/example-datasets/gbr4_simple_2022-10-31.nc' dataset = emsarray.open_dataset(dataset_url).isel(time=12) # Select only the variables we want to plot. dataset = dataset.ems.select_variables(['botz', 'temp', 'eta']) # The depth coordinate has positive=up, while the bathymetry has positive=down. # This causes issues when drawing the ocean floor. # Lets fix the depth coordinate. dataset = depth.normalize_depth_variables(dataset, ['zc'], positive_down=True) # Cross section plots need bounds information, so lets invent some dataset = utils.estimate_bounds_1d(dataset, 'zc') .. GENERATED FROM PYTHON SOURCE LINES 29-32 The following is a :mod:`transect ` path starting in the Great Sandy Strait near K'gari, heading roughly North out to deeper waters: .. GENERATED FROM PYTHON SOURCE LINES 32-54 .. code-block:: Python north_transect = transect.Transect(dataset, shapely.LineString([ [152.9768944, -25.4827962], [152.9701996, -25.4420345], [152.9727745, -25.3967620], [152.9623032, -25.3517828], [152.9401588, -25.3103560], [152.9173279, -25.2538563], [152.8962135, -25.1942238], [152.8692627, -25.0706729], [152.8623962, -24.9698750], [152.8472900, -24.8415806], [152.8308105, -24.6470172], [152.7607727, -24.3521012], [152.6392365, -24.1906056], [152.4792480, -24.0615124], ])) landmarks = [ ('Round Island', shapely.Point(152.9262543, -25.2878719)), ('Lady Elliot Island', shapely.Point(152.7145958, -24.1129146)), ] .. GENERATED FROM PYTHON SOURCE LINES 55-58 Set up three axes: one showing the transect path, one showing a temperature cross section along the transect, and one showing the sea surface height along the transect. .. GENERATED FROM PYTHON SOURCE LINES 58-66 .. code-block:: Python figure = plt.figure(figsize=(7.8, 8), layout='constrained', dpi=100) gs_root = gridspec.GridSpec(3, 1, figure=figure, height_ratios=[3, 1, 1]) path_axes = figure.add_subplot(gs_root[0], projection=dataset.ems.data_crs) temp_axes = figure.add_subplot(gs_root[1]) eta_axes = figure.add_subplot(gs_root[2], sharex=temp_axes) .. GENERATED FROM PYTHON SOURCE LINES 68-69 First make a plot showing the path of the transect overlayed on the bathymetry .. GENERATED FROM PYTHON SOURCE LINES 69-84 .. code-block:: Python path_axes.set_aspect(aspect='equal', adjustable='datalim') path_axes.set_title('Transect path') dataset.ems.make_artist( path_axes, 'botz', cmap='Blues', clim=(0, 2000), edgecolor='face', norm=PowerNorm(gamma=0.5), linewidth=0.5, zorder=0) path_axes.set_extent(plot.bounds_to_extent(north_transect.line.envelope.buffer(0.2).bounds)) path_axes.plot(*north_transect.line.coords.xy, zorder=1, c='orange', linewidth=4) plot.add_coast(path_axes, zorder=1) plot.add_gridlines(path_axes) plot.add_landmarks(path_axes, landmarks) .. GENERATED FROM PYTHON SOURCE LINES 87-89 Now plot a cross section along the transect showing the ocean temperature. As the temperature variable has a depth axis the cross section is two dimensional. .. GENERATED FROM PYTHON SOURCE LINES 89-105 .. code-block:: Python temp_axes.set_title('Temperature') dataset['temp'].attrs['units'] = '°C' dataset['zc'].attrs['long_name'] = 'Depth' north_transect.make_artist( temp_axes, 'temp', cmap='plasma') north_transect.make_ocean_floor_artist( temp_axes, dataset['botz']) # yaxis transect.setup_depth_axis( north_transect, temp_axes, data_array='temp', label='Depth', ylim=(50, -1.5)) .. GENERATED FROM PYTHON SOURCE LINES 108-111 Now plot the sea surface height along the transect. As the sea surface height does not have a depth axis the transect is one dimensional. .. GENERATED FROM PYTHON SOURCE LINES 111-124 .. code-block:: Python eta_axes.set_title('Sea surface height') eta_artist = north_transect.make_artist( eta_axes, data_array=dataset['eta']) # xaxis transect.setup_distance_axis(north_transect, eta_axes) # yaxis eta_axes.set_ylim(-0.5, 1.5) eta_axes.set_ylabel('Height above\nmean sea level') eta_axes.axhline(0, linestyle='--', color='lightgrey') eta_axes.yaxis.set_major_formatter("{x:.2g} m") .. GENERATED FROM PYTHON SOURCE LINES 127-129 The last step is to add some landmarks along the top border of the axes to help viewers link the distance along transect path to geographic locations. .. GENERATED FROM PYTHON SOURCE LINES 129-138 .. code-block:: Python top_axis = temp_axes.secondary_xaxis('top') top_axis.set_ticks( [north_transect.distance_along_line(point) for label, point in landmarks], [label for label, point in landmarks], ) plt.show() .. image-sg:: /examples/images/sphx_glr_plot-kgari-transect_001.png :alt: Transect path, Temperature, Sea surface height :srcset: /examples/images/sphx_glr_plot-kgari-transect_001.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 15.953 seconds) .. _sphx_glr_download_examples_plot-kgari-transect.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: plot-kgari-transect.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: plot-kgari-transect.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: plot-kgari-transect.zip ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_