.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "examples/00_misc/02_check_rand_meth_sampling.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_examples_00_misc_02_check_rand_meth_sampling.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_examples_00_misc_02_check_rand_meth_sampling.py:


Check Random Sampling
---------------------

.. GENERATED FROM PYTHON SOURCE LINES 5-69



.. image-sg:: /examples/00_misc/images/sphx_glr_02_check_rand_meth_sampling_001.png
   :alt: Direction sampling, Radius samples shown 781/1000
   :srcset: /examples/00_misc/images/sphx_glr_02_check_rand_meth_sampling_001.png
   :class: sphx-glr-single-img





.. code-block:: Python


    import numpy as np
    from matplotlib import pyplot as plt
    from mpl_toolkits.mplot3d import Axes3D

    import gstools as gs


    def norm_rad(vec):
        """Direction on the unit sphere."""
        vec = np.array(vec, ndmin=2)
        norm = np.zeros(vec.shape[1])
        for i in range(vec.shape[0]):
            norm += vec[i] ** 2
        norm = np.sqrt(norm)
        return np.einsum("j,ij->ij", 1 / norm, vec), norm


    def plot_rand_meth_samples(generator):
        """Plot the samples of the rand meth class."""
        norm, rad = norm_rad(generator._cov_sample)

        fig = plt.figure(figsize=(10, 4))

        if generator.model.dim == 3:
            ax = fig.add_subplot(121, projection=Axes3D.name)
            u = np.linspace(0, 2 * np.pi, 100)
            v = np.linspace(0, np.pi, 100)
            x = np.outer(np.cos(u), np.sin(v))
            y = np.outer(np.sin(u), np.sin(v))
            z = np.outer(np.ones(np.size(u)), np.cos(v))
            ax.plot_surface(x, y, z, rstride=4, cstride=4, color="b", alpha=0.1)
            ax.scatter(norm[0], norm[1], norm[2])
        elif generator.model.dim == 2:
            ax = fig.add_subplot(121)
            u = np.linspace(0, 2 * np.pi, 100)
            x = np.cos(u)
            y = np.sin(u)
            ax.plot(x, y, color="b", alpha=0.1)
            ax.scatter(norm[0], norm[1])
            ax.set_aspect("equal")
        else:
            ax = fig.add_subplot(121)
            ax.bar(-1, np.sum(np.isclose(norm, -1)), color="C0")
            ax.bar(1, np.sum(np.isclose(norm, 1)), color="C0")
            ax.set_xticks([-1, 1])
            ax.set_xticklabels(("-1", "1"))
        ax.set_title("Direction sampling")

        ax = fig.add_subplot(122)
        x = np.linspace(0, 10 / generator.model.integral_scale)
        y = generator.model.spectral_rad_pdf(x)
        ax.plot(x, y, label="radial spectral density")
        sample_in = np.sum(rad <= np.max(x))
        ax.hist(rad[rad <= np.max(x)], bins=sample_in // 50, density=True)
        ax.set_xlim([0, np.max(x)])
        ax.set_title(f"Radius samples shown {sample_in}/{len(rad)}")
        ax.legend()
        plt.show()


    model = gs.Stable(dim=3, alpha=1.5)
    srf = gs.SRF(model, seed=2020)
    plot_rand_meth_samples(srf.generator)


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

   **Total running time of the script:** (0 minutes 0.271 seconds)


.. _sphx_glr_download_examples_00_misc_02_check_rand_meth_sampling.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

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

      :download:`Download Jupyter notebook: 02_check_rand_meth_sampling.ipynb <02_check_rand_meth_sampling.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: 02_check_rand_meth_sampling.py <02_check_rand_meth_sampling.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: 02_check_rand_meth_sampling.zip <02_check_rand_meth_sampling.zip>`


.. only:: html

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

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_