===================
NEXRAD Level 3 File
===================
`Notebook <http://nbviewer.ipython.org/github/metpy/MetPy/blob/master/examples/notebooks/NEXRAD_Level_3_File.ipynb>`_

.. code:: ipython3

    import numpy as np
    import matplotlib.pyplot as plt
    from numpy import ma
    
    from metpy.cbook import get_test_data
    from metpy.io.nexrad import Level3File
    from metpy.plots import ctables

.. code:: ipython3

    fig, axes = plt.subplots(1, 2, figsize=(15, 8))
    for v, ctable, ax in zip(('N0Q', 'N0U'), ('NWSReflectivity', 'NWSVelocity'), axes):
        # Open the file
        name = get_test_data('nids/KOUN_SDUS54_%sTLX_201305202016' % v, as_file_obj=False)
        f = Level3File(name)
    
        # Pull the data out of the file object
        datadict = f.sym_block[0][0]
    
        # Turn into an array, then mask
        data = ma.array(datadict['data'])
        data[data==0] = ma.masked
    
        # Grab azimuths and calculate a range based on number of gates
        az = np.array(datadict['start_az'] + [datadict['end_az'][-1]])
        rng = np.linspace(0, f.max_range, data.shape[-1] + 1)
    
        # Convert az,range to x,y
        xlocs = rng * np.sin(np.deg2rad(az[:, np.newaxis]))
        ylocs = rng * np.cos(np.deg2rad(az[:, np.newaxis]))
       
        # Plot the data
        norm, cmap = ctables.registry.get_with_steps(ctable, 16, 16)
        ax.pcolormesh(xlocs, ylocs, data, norm=norm, cmap=cmap)
        ax.set_aspect('equal', 'datalim')
        ax.set_xlim(-40, 20)
        ax.set_ylim(-30, 30)
    
    plt.show()



.. image:: NEXRAD_Level_3_File_files/NEXRAD_Level_3_File_1_0.png