iris_Chapter7211.py

#!/usr/bin/env python3

""" 7.2.1.1. Multi-line plot"""
"""Multi-line temperature profile plot"""

import matplotlib.pyplot as plt

import iris
import iris.plot as iplt
import iris.quickplot as qplt

def main():
    fname = iris.sample_data_path('air_temp.pp')
    
    # Load exactly one cube from the given file
    temperature = iris.load_cube(fname)
    
    # We only want a small number of latitudes, so filter some out
    # using "extract"
    temperature = temperature.extract(
    iris.Constraint(latitude=lambda cell: 68 <= cell < 78))
    # lat = temperature.coord('latitude')
    # b = lat.points
    
    for cube in temperature.slices('longitude'):
        
        # Create a string label to identify this cube (i.e. latitude: value)
        cube_label = 'latitude: %s' % cube.coord('latitude').points[0]
        
        # Plot the cube, and associate it with a label
        qplt.plot(cube, label=cube_label)
            
    # Add the legend with 2 columns
    plt.legend(ncol=2)
    
    # Put a grid on the plot
    plt.grid(True)
    
    # Tell matplotlib not to extend the plot axes range to nicely
    # rounded numbers
    plt.axis('tight')
    
    # Finally, show it
    iplt.show()

# for the script is run from the comand line
if __name__ == '__main':
    main()