.. 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_anscombe.py: ================== Anscombe's Quartet ================== .. image:: /gallery/specialty_plots/images/sphx_glr_anscombe_001.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out Out: .. code-block:: none mean=7.50, std=1.94, r=0.82 mean=7.50, std=1.94, r=0.82 mean=7.50, std=1.94, r=0.82 mean=7.50, std=1.94, r=0.82 | .. code-block:: default """ Edward Tufte uses this example from Anscombe to show 4 datasets of x and y that have the same mean, standard deviation, and regression line, but which are qualitatively different. """ import matplotlib.pyplot as plt import numpy as np x = [10, 8, 13, 9, 11, 14, 6, 4, 12, 7, 5] y1 = [8.04, 6.95, 7.58, 8.81, 8.33, 9.96, 7.24, 4.26, 10.84, 4.82, 5.68] y2 = [9.14, 8.14, 8.74, 8.77, 9.26, 8.10, 6.13, 3.10, 9.13, 7.26, 4.74] y3 = [7.46, 6.77, 12.74, 7.11, 7.81, 8.84, 6.08, 5.39, 8.15, 6.42, 5.73] x4 = [8, 8, 8, 8, 8, 8, 8, 19, 8, 8, 8] y4 = [6.58, 5.76, 7.71, 8.84, 8.47, 7.04, 5.25, 12.50, 5.56, 7.91, 6.89] def fit(x): return 3 + 0.5 * x fig, axs = plt.subplots(2, 2, sharex=True, sharey=True) axs[0, 0].set(xlim=(0, 20), ylim=(2, 14)) axs[0, 0].set(xticks=(0, 10, 20), yticks=(4, 8, 12)) xfit = np.array([np.min(x), np.max(x)]) axs[0, 0].plot(x, y1, 'ks', xfit, fit(xfit), 'r-', lw=2) axs[0, 1].plot(x, y2, 'ks', xfit, fit(xfit), 'r-', lw=2) axs[1, 0].plot(x, y3, 'ks', xfit, fit(xfit), 'r-', lw=2) xfit = np.array([np.min(x4), np.max(x4)]) axs[1, 1].plot(x4, y4, 'ks', xfit, fit(xfit), 'r-', lw=2) for ax, label in zip(axs.flat, ['I', 'II', 'III', 'IV']): ax.label_outer() ax.text(3, 12, label, fontsize=20) # verify the stats pairs = (x, y1), (x, y2), (x, y3), (x4, y4) for x, y in pairs: print('mean=%1.2f, std=%1.2f, r=%1.2f' % (np.mean(y), np.std(y), np.corrcoef(x, y)[0][1])) plt.show() .. _sphx_glr_download_gallery_specialty_plots_anscombe.py: .. only :: html .. container:: sphx-glr-footer :class: sphx-glr-footer-example .. container:: sphx-glr-download :download:`Download Python source code: anscombe.py ` .. container:: sphx-glr-download :download:`Download Jupyter notebook: anscombe.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature Keywords: matplotlib code example, codex, python plot, pyplot `Gallery generated by Sphinx-Gallery `_