.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "gallery/images_contours_and_fields/tripcolor_demo.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. meta:: :keywords: codex .. 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_gallery_images_contours_and_fields_tripcolor_demo.py: ============== Tripcolor Demo ============== Pseudocolor plots of unstructured triangular grids. .. GENERATED FROM PYTHON SOURCE LINES 8-13 .. code-block:: Python import matplotlib.pyplot as plt import numpy as np import matplotlib.tri as tri .. GENERATED FROM PYTHON SOURCE LINES 14-16 Creating a Triangulation without specifying the triangles results in the Delaunay triangulation of the points. .. GENERATED FROM PYTHON SOURCE LINES 16-39 .. code-block:: Python # First create the x and y coordinates of the points. n_angles = 36 n_radii = 8 min_radius = 0.25 radii = np.linspace(min_radius, 0.95, n_radii) angles = np.linspace(0, 2 * np.pi, n_angles, endpoint=False) angles = np.repeat(angles[..., np.newaxis], n_radii, axis=1) angles[:, 1::2] += np.pi / n_angles x = (radii * np.cos(angles)).flatten() y = (radii * np.sin(angles)).flatten() z = (np.cos(radii) * np.cos(3 * angles)).flatten() # Create the Triangulation; no triangles so Delaunay triangulation created. triang = tri.Triangulation(x, y) # Mask off unwanted triangles. triang.set_mask(np.hypot(x[triang.triangles].mean(axis=1), y[triang.triangles].mean(axis=1)) < min_radius) .. GENERATED FROM PYTHON SOURCE LINES 40-41 tripcolor plot. .. GENERATED FROM PYTHON SOURCE LINES 41-48 .. code-block:: Python fig1, ax1 = plt.subplots() ax1.set_aspect('equal') tpc = ax1.tripcolor(triang, z, shading='flat') fig1.colorbar(tpc) ax1.set_title('tripcolor of Delaunay triangulation, flat shading') .. image-sg:: /gallery/images_contours_and_fields/images/sphx_glr_tripcolor_demo_001.png :alt: tripcolor of Delaunay triangulation, flat shading :srcset: /gallery/images_contours_and_fields/images/sphx_glr_tripcolor_demo_001.png, /gallery/images_contours_and_fields/images/sphx_glr_tripcolor_demo_001_2_00x.png 2.00x :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 49-50 Illustrate Gouraud shading. .. GENERATED FROM PYTHON SOURCE LINES 50-58 .. code-block:: Python fig2, ax2 = plt.subplots() ax2.set_aspect('equal') tpc = ax2.tripcolor(triang, z, shading='gouraud') fig2.colorbar(tpc) ax2.set_title('tripcolor of Delaunay triangulation, gouraud shading') .. image-sg:: /gallery/images_contours_and_fields/images/sphx_glr_tripcolor_demo_002.png :alt: tripcolor of Delaunay triangulation, gouraud shading :srcset: /gallery/images_contours_and_fields/images/sphx_glr_tripcolor_demo_002.png, /gallery/images_contours_and_fields/images/sphx_glr_tripcolor_demo_002_2_00x.png 2.00x :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 59-63 You can specify your own triangulation rather than perform a Delaunay triangulation of the points, where each triangle is given by the indices of the three points that make up the triangle, ordered in either a clockwise or anticlockwise manner. .. GENERATED FROM PYTHON SOURCE LINES 63-111 .. code-block:: Python xy = np.asarray([ [-0.101, 0.872], [-0.080, 0.883], [-0.069, 0.888], [-0.054, 0.890], [-0.045, 0.897], [-0.057, 0.895], [-0.073, 0.900], [-0.087, 0.898], [-0.090, 0.904], [-0.069, 0.907], [-0.069, 0.921], [-0.080, 0.919], [-0.073, 0.928], [-0.052, 0.930], [-0.048, 0.942], [-0.062, 0.949], [-0.054, 0.958], [-0.069, 0.954], [-0.087, 0.952], [-0.087, 0.959], [-0.080, 0.966], [-0.085, 0.973], [-0.087, 0.965], [-0.097, 0.965], [-0.097, 0.975], [-0.092, 0.984], [-0.101, 0.980], [-0.108, 0.980], [-0.104, 0.987], [-0.102, 0.993], [-0.115, 1.001], [-0.099, 0.996], [-0.101, 1.007], [-0.090, 1.010], [-0.087, 1.021], [-0.069, 1.021], [-0.052, 1.022], [-0.052, 1.017], [-0.069, 1.010], [-0.064, 1.005], [-0.048, 1.005], [-0.031, 1.005], [-0.031, 0.996], [-0.040, 0.987], [-0.045, 0.980], [-0.052, 0.975], [-0.040, 0.973], [-0.026, 0.968], [-0.020, 0.954], [-0.006, 0.947], [ 0.003, 0.935], [ 0.006, 0.926], [ 0.005, 0.921], [ 0.022, 0.923], [ 0.033, 0.912], [ 0.029, 0.905], [ 0.017, 0.900], [ 0.012, 0.895], [ 0.027, 0.893], [ 0.019, 0.886], [ 0.001, 0.883], [-0.012, 0.884], [-0.029, 0.883], [-0.038, 0.879], [-0.057, 0.881], [-0.062, 0.876], [-0.078, 0.876], [-0.087, 0.872], [-0.030, 0.907], [-0.007, 0.905], [-0.057, 0.916], [-0.025, 0.933], [-0.077, 0.990], [-0.059, 0.993]]) x, y = np.rad2deg(xy).T triangles = np.asarray([ [67, 66, 1], [65, 2, 66], [ 1, 66, 2], [64, 2, 65], [63, 3, 64], [60, 59, 57], [ 2, 64, 3], [ 3, 63, 4], [ 0, 67, 1], [62, 4, 63], [57, 59, 56], [59, 58, 56], [61, 60, 69], [57, 69, 60], [ 4, 62, 68], [ 6, 5, 9], [61, 68, 62], [69, 68, 61], [ 9, 5, 70], [ 6, 8, 7], [ 4, 70, 5], [ 8, 6, 9], [56, 69, 57], [69, 56, 52], [70, 10, 9], [54, 53, 55], [56, 55, 53], [68, 70, 4], [52, 56, 53], [11, 10, 12], [69, 71, 68], [68, 13, 70], [10, 70, 13], [51, 50, 52], [13, 68, 71], [52, 71, 69], [12, 10, 13], [71, 52, 50], [71, 14, 13], [50, 49, 71], [49, 48, 71], [14, 16, 15], [14, 71, 48], [17, 19, 18], [17, 20, 19], [48, 16, 14], [48, 47, 16], [47, 46, 16], [16, 46, 45], [23, 22, 24], [21, 24, 22], [17, 16, 45], [20, 17, 45], [21, 25, 24], [27, 26, 28], [20, 72, 21], [25, 21, 72], [45, 72, 20], [25, 28, 26], [44, 73, 45], [72, 45, 73], [28, 25, 29], [29, 25, 31], [43, 73, 44], [73, 43, 40], [72, 73, 39], [72, 31, 25], [42, 40, 43], [31, 30, 29], [39, 73, 40], [42, 41, 40], [72, 33, 31], [32, 31, 33], [39, 38, 72], [33, 72, 38], [33, 38, 34], [37, 35, 38], [34, 38, 35], [35, 37, 36]]) xmid = x[triangles].mean(axis=1) ymid = y[triangles].mean(axis=1) x0 = -5 y0 = 52 zfaces = np.exp(-0.01 * ((xmid - x0) * (xmid - x0) + (ymid - y0) * (ymid - y0))) .. GENERATED FROM PYTHON SOURCE LINES 112-118 Rather than create a Triangulation object, can simply pass x, y and triangles arrays to tripcolor directly. It would be better to use a Triangulation object if the same triangulation was to be used more than once to save duplicated calculations. Can specify one color value per face rather than one per point by using the *facecolors* keyword argument. .. GENERATED FROM PYTHON SOURCE LINES 118-129 .. code-block:: Python fig3, ax3 = plt.subplots() ax3.set_aspect('equal') tpc = ax3.tripcolor(x, y, triangles, facecolors=zfaces, edgecolors='k') fig3.colorbar(tpc) ax3.set_title('tripcolor of user-specified triangulation') ax3.set_xlabel('Longitude (degrees)') ax3.set_ylabel('Latitude (degrees)') plt.show() .. image-sg:: /gallery/images_contours_and_fields/images/sphx_glr_tripcolor_demo_003.png :alt: tripcolor of user-specified triangulation :srcset: /gallery/images_contours_and_fields/images/sphx_glr_tripcolor_demo_003.png, /gallery/images_contours_and_fields/images/sphx_glr_tripcolor_demo_003_2_00x.png 2.00x :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 130-138 .. admonition:: References The use of the following functions, methods, classes and modules is shown in this example: - `matplotlib.axes.Axes.tripcolor` / `matplotlib.pyplot.tripcolor` - `matplotlib.tri` - `matplotlib.tri.Triangulation` .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 1.792 seconds) .. _sphx_glr_download_gallery_images_contours_and_fields_tripcolor_demo.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: tripcolor_demo.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: tripcolor_demo.py ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_