""" ================ The Sankey class ================ Demonstrate the Sankey class by producing three basic diagrams. """ 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. 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.") # %% # 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 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') # %% # 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 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() # %% # 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. plt.show() # %% # # .. admonition:: References # # The use of the following functions, methods, classes and modules is shown # in this example: # # - `matplotlib.sankey` # - `matplotlib.sankey.Sankey` # - `matplotlib.sankey.Sankey.add` # - `matplotlib.sankey.Sankey.finish`