===================
NEXRAD Level 3 File
===================
.. code:: python

    import numpy as np
    import matplotlib.pyplot as plt
    from numpy import ma
    
    from metpy.io.nexrad import Level3File

.. code:: python

    # Open the file
    name = '../testdata/Level3_FFC_N0Q_20140407_1805.nids'
    f = Level3File(name)

.. code:: python

    # Pull the data out of the file object
    datadict = f.sym_block[0][0]
    
    # Turn into an array, then mask
    ref = ma.array(datadict['data'])
    ref[ref==32770] = ma.masked

.. code:: python

    # Grab azimuths and calculate a range based on number of gates
    az = np.array(datadict['start_az'] + [datadict['end_az'][-1]])
    rng = np.arange(ref.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]))

.. code:: python

    # Plot -- ref units are raw 8-bit values, not floats
    fig = plt.figure(figsize=(9, 8))
    plt.pcolormesh(xlocs, ylocs, ref)
    plt.colorbar()
    plt.axis('equal')
    plt.show()



.. image:: NEXRAD_Level_3_File_files/NEXRAD_Level_3_File_4_0.png