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

.. only:: html

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

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

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

.. _sphx_glr_auto_graphs_plot_graphs_fill_area.py:


How to fill an area
===================

.. GENERATED FROM PYTHON SOURCE LINES 5-6

.. code-block:: Python

    # sphinx_gallery_thumbnail_number = 2







.. GENERATED FROM PYTHON SOURCE LINES 9-10

In this example, we show how to fill specified area with a given color.

.. GENERATED FROM PYTHON SOURCE LINES 12-18

.. code-block:: Python

    import openturns as ot
    import openturns.viewer as viewer
    from matplotlib import pylab as plt

    ot.Log.Show(ot.Log.NONE)








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We generate a sample from a standard gaussian distribution.

.. GENERATED FROM PYTHON SOURCE LINES 22-26

.. code-block:: Python

    dist = ot.Normal()
    graph = dist.drawPDF()
    view = viewer.View(graph)




.. image-sg:: /auto_graphs/images/sphx_glr_plot_graphs_fill_area_001.png
   :alt: plot graphs fill area
   :srcset: /auto_graphs/images/sphx_glr_plot_graphs_fill_area_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 27-38

.. code-block:: Python



    def linearSample(xmin, xmax, npoints):
        """Returns a sample created from a regular grid
        from xmin to xmax with npoints points."""
        step = (xmax - xmin) / (npoints - 1)
        rg = ot.RegularGrid(xmin, step, npoints)
        vertices = rg.getVertices()
        return vertices









.. GENERATED FROM PYTHON SOURCE LINES 39-42

.. code-block:: Python

    a = 1.0
    b = 2.0








.. GENERATED FROM PYTHON SOURCE LINES 43-48

.. code-block:: Python

    nplot = 100  # Number of points in the plot
    x = linearSample(a, b, nplot)
    y = dist.computePDF(x)









.. GENERATED FROM PYTHON SOURCE LINES 49-50

The following function uses the `PolygonArray` class to create a area filled with a given color.

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.. code-block:: Python

    def drawInTheBounds(vLow, vUp, n_test):
        """
        Draw the area within the bounds.
        """
        palette = ot.Drawable.BuildDefaultPalette(2)
        myPaletteColor = palette[1]
        polyData = [[vLow[i], vLow[i + 1], vUp[i + 1], vUp[i]] for i in range(n_test - 1)]
        polygonList = [
            ot.Polygon(polyData[i], myPaletteColor, myPaletteColor)
            for i in range(n_test - 1)
        ]
        boundsPoly = ot.PolygonArray(polygonList)
        return boundsPoly









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Compute the bounds to fill: the lower vertical bound is zero and the upper vertical bound is the PDF.

.. GENERATED FROM PYTHON SOURCE LINES 72-75

.. code-block:: Python

    vLow = [[x[i, 0], 0.0] for i in range(nplot)]
    vUp = [[x[i, 0], y[i, 0]] for i in range(nplot)]








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.. code-block:: Python

    area = dist.computeCDF(b) - dist.computeCDF(a)








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.. code-block:: Python

    boundsPoly = drawInTheBounds(vLow, vUp, nplot)
    graph = dist.drawPDF()
    graph.add(boundsPoly)
    graph.setTitle("Area = %.3f" % (area))
    graph.setLegends([""])
    view = viewer.View(graph)
    plt.show()




.. image-sg:: /auto_graphs/images/sphx_glr_plot_graphs_fill_area_002.png
   :alt: Area = 0.136
   :srcset: /auto_graphs/images/sphx_glr_plot_graphs_fill_area_002.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 88-89

The CDF difference is equal to the area under the curve.


.. _sphx_glr_download_auto_graphs_plot_graphs_fill_area.py:

.. only:: html

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

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

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

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

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