.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "gallery/misc/rasterization_demo.py" .. LINE NUMBERS ARE GIVEN BELOW. .. 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_misc_rasterization_demo.py: ================================= Rasterization for vector graphics ================================= Rasterization converts vector graphics into a raster image (pixels). It can speed up rendering and produce smaller files for large data sets, but comes at the cost of a fixed resolution. Whether rasterization should be used can be specified per artist. This can be useful to reduce the file size of large artists, while maintaining the advantages of vector graphics for other artists such as the axes and text. For instance a complicated `~.Axes.pcolormesh` or `~.Axes.contourf` can be made significantly simpler by rasterizing. Setting rasterization only affects vector backends such as PDF, SVG, or PS. Rasterization is disabled by default. There are two ways to enable it, which can also be combined: - Set `~.Artist.set_rasterized` on individual artists, or use the keyword argument *rasterized* when creating the artist. - Set `.Axes.set_rasterization_zorder` to rasterize all artists with a zorder less than the given value. The storage size and the resolution of the rasterized artist is determined by its physical size and the value of the ``dpi`` parameter passed to `~.Figure.savefig`. .. note:: The image of this example shown in the HTML documentation is not a vector graphic. Therefore, it cannot illustrate the rasterization effect. Please run this example locally and check the generated graphics files. .. GENERATED FROM PYTHON SOURCE LINES 36-85 .. code-block:: default import numpy as np import matplotlib.pyplot as plt d = np.arange(100).reshape(10, 10) # the values to be color-mapped x, y = np.meshgrid(np.arange(11), np.arange(11)) theta = 0.25*np.pi xx = x*np.cos(theta) - y*np.sin(theta) # rotate x by -theta yy = x*np.sin(theta) + y*np.cos(theta) # rotate y by -theta fig, ((ax1, ax2), (ax3, ax4)) = plt.subplots(2, 2, constrained_layout=True) # pcolormesh without rasterization ax1.set_aspect(1) ax1.pcolormesh(xx, yy, d) ax1.set_title("No Rasterization") # pcolormesh with rasterization; enabled by keyword argument ax2.set_aspect(1) ax2.set_title("Rasterization") m = ax2.pcolormesh(xx, yy, d, rasterized=True) # pcolormesh with an overlaid text without rasterization ax3.set_aspect(1) ax3.pcolormesh(xx, yy, d) ax3.text(0.5, 0.5, "Text", alpha=0.2, va="center", ha="center", size=50, transform=ax3.transAxes) ax3.set_title("No Rasterization") # pcolormesh with an overlaid text without rasterization; enabled by zorder. # Setting the rasterization zorder threshold to 0 and a negative zorder on the # pcolormesh rasterizes it. All artists have a non-negative zorder by default, # so they (e.g. the text here) are not affected. ax4.set_aspect(1) m = ax4.pcolormesh(xx, yy, d, zorder=-10) ax4.text(0.5, 0.5, "Text", alpha=0.2, va="center", ha="center", size=50, transform=ax4.transAxes) ax4.set_rasterization_zorder(0) ax4.set_title("Rasterization z$<-10$") # Save files in pdf and eps format plt.savefig("test_rasterization.pdf", dpi=150) plt.savefig("test_rasterization.eps", dpi=150) if not plt.rcParams["text.usetex"]: plt.savefig("test_rasterization.svg", dpi=150) # svg backend currently ignores the dpi .. image:: /gallery/misc/images/sphx_glr_rasterization_demo_001.png :alt: No Rasterization, Rasterization, No Rasterization, Rasterization z$<-10$ :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out Out: .. code-block:: none The PostScript backend does not support transparency; partially transparent artists will be rendered opaque. The PostScript backend does not support transparency; partially transparent artists will be rendered opaque. .. GENERATED FROM PYTHON SOURCE LINES 86-94 .. admonition:: References The use of the following functions, methods, classes and modules is shown in this example: - `matplotlib.artist.Artist.set_rasterized` - `matplotlib.axes.Axes.set_rasterization_zorder` - `matplotlib.axes.Axes.pcolormesh` / `matplotlib.pyplot.pcolormesh` .. rst-class:: sphx-glr-timing **Total running time of the script:** ( 0 minutes 1.354 seconds) .. _sphx_glr_download_gallery_misc_rasterization_demo.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: rasterization_demo.py ` .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: rasterization_demo.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature Keywords: matplotlib code example, codex, python plot, pyplot `Gallery generated by Sphinx-Gallery `_