Connection styles for annotations

When creating an annotation using annotate, the arrow shape can be controlled via the connectionstyle parameter of arrowprops. For further details see the description of FancyArrowPatch.

import matplotlib.pyplot as plt


def demo_con_style(ax, connectionstyle):
    x1, y1 = 0.3, 0.2
    x2, y2 = 0.8, 0.6

    ax.plot([x1, x2], [y1, y2], ".")
    ax.annotate("",
                xy=(x1, y1), xycoords='data',
                xytext=(x2, y2), textcoords='data',
                arrowprops=dict(arrowstyle="->", color="0.5",
                                shrinkA=5, shrinkB=5,
                                patchA=None, patchB=None,
                                connectionstyle=connectionstyle,
                                ),
                )

    ax.text(.05, .95, connectionstyle.replace(",", ",\n"),
            transform=ax.transAxes, ha="left", va="top")


fig, axs = plt.subplots(3, 5, figsize=(7, 6.3), constrained_layout=True)
demo_con_style(axs[0, 0], "angle3,angleA=90,angleB=0")
demo_con_style(axs[1, 0], "angle3,angleA=0,angleB=90")
demo_con_style(axs[0, 1], "arc3,rad=0.")
demo_con_style(axs[1, 1], "arc3,rad=0.3")
demo_con_style(axs[2, 1], "arc3,rad=-0.3")
demo_con_style(axs[0, 2], "angle,angleA=-90,angleB=180,rad=0")
demo_con_style(axs[1, 2], "angle,angleA=-90,angleB=180,rad=5")
demo_con_style(axs[2, 2], "angle,angleA=-90,angleB=10,rad=5")
demo_con_style(axs[0, 3], "arc,angleA=-90,angleB=0,armA=30,armB=30,rad=0")
demo_con_style(axs[1, 3], "arc,angleA=-90,angleB=0,armA=30,armB=30,rad=5")
demo_con_style(axs[2, 3], "arc,angleA=-90,angleB=0,armA=0,armB=40,rad=0")
demo_con_style(axs[0, 4], "bar,fraction=0.3")
demo_con_style(axs[1, 4], "bar,fraction=-0.3")
demo_con_style(axs[2, 4], "bar,angle=180,fraction=-0.2")

for ax in axs.flat:
    ax.set(xlim=(0, 1), ylim=(0, 1.25), xticks=[], yticks=[], aspect=1.25)
fig.set_constrained_layout_pads(wspace=0, hspace=0, w_pad=0, h_pad=0)

plt.show()

References

The use of the following functions, methods, classes and modules is shown in this example:

• matplotlib.axes.Axes.annotate

• matplotlib.patches.FancyArrowPatch