.. only:: html .. note:: :class: sphx-glr-download-link-note Click :ref:`here ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_gallery_specialty_plots_sankey_basics.py: ================ The Sankey class ================ Demonstrate the Sankey class by producing three basic diagrams. .. code-block:: default import matplotlib.pyplot as plt from matplotlib.sankey import Sankey Example 1 -- Mostly defaults This demonstrates how to create a simple diagram by implicitly calling the Sankey.add() method and by appending finish() to the call to the class. .. code-block:: default Sankey(flows=[0.25, 0.15, 0.60, -0.20, -0.15, -0.05, -0.50, -0.10], labels=['', '', '', 'First', 'Second', 'Third', 'Fourth', 'Fifth'], orientations=[-1, 1, 0, 1, 1, 1, 0, -1]).finish() plt.title("The default settings produce a diagram like this.") .. image:: /gallery/specialty_plots/images/sphx_glr_sankey_basics_001.png :alt: The default settings produce a diagram like this. :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out Out: .. code-block:: none Text(0.5, 1.0, 'The default settings produce a diagram like this.') Notice: 1. Axes weren't provided when Sankey() was instantiated, so they were created automatically. 2. The scale argument wasn't necessary since the data was already normalized. 3. By default, the lengths of the paths are justified. Example 2 This demonstrates: 1. Setting one path longer than the others 2. Placing a label in the middle of the diagram 3. Using the scale argument to normalize the flows 4. Implicitly passing keyword arguments to PathPatch() 5. Changing the angle of the arrow heads 6. Changing the offset between the tips of the paths and their labels 7. Formatting the numbers in the path labels and the associated unit 8. Changing the appearance of the patch and the labels after the figure is created .. code-block:: default fig = plt.figure() ax = fig.add_subplot(1, 1, 1, xticks=[], yticks=[], title="Flow Diagram of a Widget") sankey = Sankey(ax=ax, scale=0.01, offset=0.2, head_angle=180, format='%.0f', unit='%') sankey.add(flows=[25, 0, 60, -10, -20, -5, -15, -10, -40], labels=['', '', '', 'First', 'Second', 'Third', 'Fourth', 'Fifth', 'Hurray!'], orientations=[-1, 1, 0, 1, 1, 1, -1, -1, 0], pathlengths=[0.25, 0.25, 0.25, 0.25, 0.25, 0.6, 0.25, 0.25, 0.25], patchlabel="Widget\nA") # Arguments to matplotlib.patches.PathPatch diagrams = sankey.finish() diagrams[0].texts[-1].set_color('r') diagrams[0].text.set_fontweight('bold') .. image:: /gallery/specialty_plots/images/sphx_glr_sankey_basics_002.png :alt: Flow Diagram of a Widget :class: sphx-glr-single-img Notice: 1. Since the sum of the flows is nonzero, the width of the trunk isn't uniform. The matplotlib logging system logs this at the DEBUG level. 2. The second flow doesn't appear because its value is zero. Again, this is logged at the DEBUG level. Example 3 This demonstrates: 1. Connecting two systems 2. Turning off the labels of the quantities 3. Adding a legend .. code-block:: default fig = plt.figure() ax = fig.add_subplot(1, 1, 1, xticks=[], yticks=[], title="Two Systems") flows = [0.25, 0.15, 0.60, -0.10, -0.05, -0.25, -0.15, -0.10, -0.35] sankey = Sankey(ax=ax, unit=None) sankey.add(flows=flows, label='one', orientations=[-1, 1, 0, 1, 1, 1, -1, -1, 0]) sankey.add(flows=[-0.25, 0.15, 0.1], label='two', orientations=[-1, -1, -1], prior=0, connect=(0, 0)) diagrams = sankey.finish() diagrams[-1].patch.set_hatch('/') plt.legend() .. image:: /gallery/specialty_plots/images/sphx_glr_sankey_basics_003.png :alt: Two Systems :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out Out: .. code-block:: none Notice that only one connection is specified, but the systems form a circuit since: (1) the lengths of the paths are justified and (2) the orientation and ordering of the flows is mirrored. .. code-block:: default plt.show() ------------ References """""""""" The use of the following functions, methods, classes and modules is shown in this example: .. code-block:: default import matplotlib matplotlib.sankey matplotlib.sankey.Sankey matplotlib.sankey.Sankey.add matplotlib.sankey.Sankey.finish .. rst-class:: sphx-glr-script-out Out: .. code-block:: none .. _sphx_glr_download_gallery_specialty_plots_sankey_basics.py: .. only :: html .. container:: sphx-glr-footer :class: sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: sankey_basics.py ` .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: sankey_basics.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature Keywords: matplotlib code example, codex, python plot, pyplot `Gallery generated by Sphinx-Gallery `_