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

.. only:: html

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

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

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

.. _sphx_glr_examples_nonnegativecoefficients.py:


=========================
Non-negative coefficients.
=========================

To illustrate how bounds can be put on coefficients,
a filter without negative coefficients is designed.

.. GENERATED FROM PYTHON SOURCE LINES 9-27

.. code-block:: Python


    import matplotlib.pyplot as plt
    from mplsignal import freqz_fir

    from fird.constraint import CoefficientBoundConstraint
    from fird.designer import FIRDesigner
    from fird.objective import PiecewiseLinearObjective

    o = PiecewiseLinearObjective([0, 0.2, 0.5, 1], [1, 1, 0, 0], [1, 10])
    c = CoefficientBoundConstraint(lower=0)
    d = FIRDesigner(21, o, c)
    d.solve()
    h = d.get_impulse_response()
    fig, ax = plt.subplots(2, 1, layout="constrained")
    freqz_fir(h, ax=ax[0], style="magnitude")
    ax[1].stem(h)
    fig.show()




.. image-sg:: /examples/images/sphx_glr_nonnegativecoefficients_001.png
   :alt: nonnegativecoefficients
   :srcset: /examples/images/sphx_glr_nonnegativecoefficients_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 28-30

This given quite bad results, but for narrow-band filters it can
be possible to get decent results.

.. GENERATED FROM PYTHON SOURCE LINES 30-40

.. code-block:: Python


    o = PiecewiseLinearObjective([0, 0.05, 0.3, 1], [1, 1, 0, 0], [1, 10])
    c = CoefficientBoundConstraint(lower=0)
    d = FIRDesigner(21, o, c)
    d.solve()
    h = d.get_impulse_response()
    fig, ax = plt.subplots(2, 1, layout="constrained")
    freqz_fir(h, ax=ax[0], style="magnitude")
    ax[1].stem(h)
    fig.show()



.. image-sg:: /examples/images/sphx_glr_nonnegativecoefficients_002.png
   :alt: nonnegativecoefficients
   :srcset: /examples/images/sphx_glr_nonnegativecoefficients_002.png
   :class: sphx-glr-single-img






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

   **Total running time of the script:** (0 minutes 0.599 seconds)


.. _sphx_glr_download_examples_nonnegativecoefficients.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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