

.. _sphx_glr_gallery_animation_strip_chart_demo.py:


============
Oscilloscope
============

Emulates an oscilloscope.




.. image:: /gallery/animation/images/sphx_glr_strip_chart_demo_001.png
    :align: center





.. code-block:: python

    import numpy as np
    from matplotlib.lines import Line2D
    import matplotlib.pyplot as plt
    import matplotlib.animation as animation


    class Scope(object):
        def __init__(self, ax, maxt=2, dt=0.02):
            self.ax = ax
            self.dt = dt
            self.maxt = maxt
            self.tdata = [0]
            self.ydata = [0]
            self.line = Line2D(self.tdata, self.ydata)
            self.ax.add_line(self.line)
            self.ax.set_ylim(-.1, 1.1)
            self.ax.set_xlim(0, self.maxt)

        def update(self, y):
            lastt = self.tdata[-1]
            if lastt > self.tdata[0] + self.maxt:  # reset the arrays
                self.tdata = [self.tdata[-1]]
                self.ydata = [self.ydata[-1]]
                self.ax.set_xlim(self.tdata[0], self.tdata[0] + self.maxt)
                self.ax.figure.canvas.draw()

            t = self.tdata[-1] + self.dt
            self.tdata.append(t)
            self.ydata.append(y)
            self.line.set_data(self.tdata, self.ydata)
            return self.line,


    def emitter(p=0.03):
        'return a random value with probability p, else 0'
        while True:
            v = np.random.rand(1)
            if v > p:
                yield 0.
            else:
                yield np.random.rand(1)

    # Fixing random state for reproducibility
    np.random.seed(19680801)


    fig, ax = plt.subplots()
    scope = Scope(ax)

    # pass a generator in "emitter" to produce data for the update func
    ani = animation.FuncAnimation(fig, scope.update, emitter, interval=10,
                                  blit=True)


    plt.show()

**Total running time of the script:** ( 0 minutes  0.065 seconds)



.. container:: sphx-glr-footer


  .. container:: sphx-glr-download

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



  .. container:: sphx-glr-download

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

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

    `Generated by Sphinx-Gallery <https://sphinx-gallery.readthedocs.io>`_
