.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "python_module/14_generic_tools/pet_fit_contour.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_python_module_14_generic_tools_pet_fit_contour.py>`
        to download the full example code. or to run this example in your browser via Binder

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

.. _sphx_glr_python_module_14_generic_tools_pet_fit_contour.py:


Contour fit
===========

Two type of fit :
 - Ellipse
 - Circle

In the two case we use a least square algorithm

.. GENERATED FROM PYTHON SOURCE LINES 11-20

.. code-block:: Python


    from matplotlib import pyplot as plt
    from numpy import cos, linspace, radians, sin

    from py_eddy_tracker import data
    from py_eddy_tracker.generic import coordinates_to_local, local_to_coordinates
    from py_eddy_tracker.observations.observation import EddiesObservations
    from py_eddy_tracker.poly import fit_circle_, fit_ellipse








.. GENERATED FROM PYTHON SOURCE LINES 21-22

Load example identification file

.. GENERATED FROM PYTHON SOURCE LINES 22-25

.. code-block:: Python

    a = EddiesObservations.load_file(data.get_demo_path("Anticyclonic_20190223.nc"))









.. GENERATED FROM PYTHON SOURCE LINES 26-27

Function to draw circle or ellipse from parameter

.. GENERATED FROM PYTHON SOURCE LINES 27-40

.. code-block:: Python

    def build_circle(x0, y0, r):
        angle = radians(linspace(0, 360, 50))
        x_norm, y_norm = cos(angle), sin(angle)
        return local_to_coordinates(x_norm * r, y_norm * r, x0, y0)


    def build_ellipse(x0, y0, a, b, theta):
        angle = radians(linspace(0, 360, 50))
        x = a * cos(theta) * cos(angle) - b * sin(theta) * sin(angle)
        y = a * sin(theta) * cos(angle) + b * cos(theta) * sin(angle)
        return local_to_coordinates(x, y, x0, y0)









.. GENERATED FROM PYTHON SOURCE LINES 41-42

Plot fitted circle or ellipse on stored contour

.. GENERATED FROM PYTHON SOURCE LINES 42-63

.. code-block:: Python

    xs, ys = a.contour_lon_s, a.contour_lat_s

    fig = plt.figure(figsize=(15, 15))

    j = 1
    for i in range(0, 800, 30):
        x, y = xs[i], ys[i]
        x0_, y0_ = x.mean(), y.mean()
        x_, y_ = coordinates_to_local(x, y, x0_, y0_)
        ax = fig.add_subplot(4, 4, j)
        ax.grid(), ax.set_aspect("equal")
        ax.plot(x, y, label="store", color="black")
        x0, y0, a, b, theta = fit_ellipse(x_, y_)
        x0, y0 = local_to_coordinates(x0, y0, x0_, y0_)
        ax.plot(*build_ellipse(x0, y0, a, b, theta), label="ellipse", color="green")
        x0, y0, radius, shape_error = fit_circle_(x_, y_)
        x0, y0 = local_to_coordinates(x0, y0, x0_, y0_)
        ax.plot(*build_circle(x0, y0, radius), label="circle", color="red", lw=0.5)
        if j == 16:
            break
        j += 1



.. image-sg:: /python_module/14_generic_tools/images/sphx_glr_pet_fit_contour_001.png
   :alt: pet fit contour
   :srcset: /python_module/14_generic_tools/images/sphx_glr_pet_fit_contour_001.png
   :class: sphx-glr-single-img






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

   **Total running time of the script:** (0 minutes 4.170 seconds)


.. _sphx_glr_download_python_module_14_generic_tools_pet_fit_contour.py:

.. only:: html

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

    .. container:: binder-badge

      .. image:: images/binder_badge_logo.svg
        :target: https://mybinder.org/v2/gh/AntSimi/py-eddy-tracker/master?urlpath=lab/tree/notebooks/python_module/14_generic_tools/pet_fit_contour.ipynb
        :alt: Launch binder
        :width: 150 px

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

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

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

      :download:`Download Python source code: pet_fit_contour.py <pet_fit_contour.py>`

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

      :download:`Download zipped: pet_fit_contour.zip <pet_fit_contour.zip>`


.. only:: html

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

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