.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        Click :ref:`here <sphx_glr_download_gallery_mplot3d_voxels_torus.py>`     to download the full example code
    .. rst-class:: sphx-glr-example-title

    .. _sphx_glr_gallery_mplot3d_voxels_torus.py:


=======================================================
3D voxel / volumetric plot with cylindrical coordinates
=======================================================

Demonstrates using the *x*, *y*, *z* parameters of `.Axes3D.voxels`.



.. image:: /gallery/mplot3d/images/sphx_glr_voxels_torus_001.png
    :alt: voxels torus
    :class: sphx-glr-single-img






.. code-block:: default


    import matplotlib.pyplot as plt
    import matplotlib.colors
    import numpy as np


    def midpoints(x):
        sl = ()
        for i in range(x.ndim):
            x = (x[sl + np.index_exp[:-1]] + x[sl + np.index_exp[1:]]) / 2.0
            sl += np.index_exp[:]
        return x

    # prepare some coordinates, and attach rgb values to each
    r, theta, z = np.mgrid[0:1:11j, 0:np.pi*2:25j, -0.5:0.5:11j]
    x = r*np.cos(theta)
    y = r*np.sin(theta)

    rc, thetac, zc = midpoints(r), midpoints(theta), midpoints(z)

    # define a wobbly torus about [0.7, *, 0]
    sphere = (rc - 0.7)**2 + (zc + 0.2*np.cos(thetac*2))**2 < 0.2**2

    # combine the color components
    hsv = np.zeros(sphere.shape + (3,))
    hsv[..., 0] = thetac / (np.pi*2)
    hsv[..., 1] = rc
    hsv[..., 2] = zc + 0.5
    colors = matplotlib.colors.hsv_to_rgb(hsv)

    # and plot everything
    fig = plt.figure()
    ax = fig.gca(projection='3d')
    ax.voxels(x, y, z, sphere,
              facecolors=colors,
              edgecolors=np.clip(2*colors - 0.5, 0, 1),  # brighter
              linewidth=0.5)

    plt.show()


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** ( 0 minutes  1.275 seconds)


.. _sphx_glr_download_gallery_mplot3d_voxels_torus.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: voxels_torus.py <voxels_torus.py>`



  .. container:: sphx-glr-download sphx-glr-download-jupyter

     :download:`Download Jupyter notebook: voxels_torus.ipynb <voxels_torus.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    Keywords: matplotlib code example, codex, python plot, pyplot
    `Gallery generated by Sphinx-Gallery
    <https://sphinx-gallery.readthedocs.io>`_