I'm attempting to use fill_between in a radar plot to paint a "ring", following the matplotlib radar example here:

CodePudding user response：

Here is a solution as suggested in my comment that relies on you providing x, y1, and y2 as args, not kwargs:

....
def fill_between(self, *args, **kwargs):
    """
    Override fill_between 
    - CUSTOM ADDITION TO EXAMPLE - 
    """
    if len(args) and args[0][0] != args[0][-1]:
        args = list(args)
        for i, arg in enumerate(args):
            args[i] = np.append(arg, arg[0])            
                              
    return super().fill_between(*args, **kwargs)
....

....
if __name__ == '__main__':
    N = 5
    theta = radar_factory(N, frame='polygon')

    data1 = [2,1.5,3,3,2]
    data2 = [1,0.5,2,2,1]
    spoke_labels = ['A', 'B', 'C', 'D', 'E']

    fig, ax = plt.subplots(figsize=(9, 9), nrows=1, ncols=1,
                             subplot_kw=dict(projection='radar'))

    ax.plot(theta, data1, color='blue')
    ax.plot(theta, data2, color='blue')
    ax.fill_between(theta, data1, data2, color='red')
    ax.fill(theta, data2, facecolor='blue', alpha=0.25)
    ax.set_varlabels(spoke_labels)

    plt.show()

Sample output:

You can easily implement also kwargs parsing for greater flexibility if needed but obviously, you lose some flexibility of matplotlib parsing. However, it still parses where if provided as arg of len N or kwarg of len N 1:

#where array provided as arg of len N
ax.fill_between(theta, data1, data2, [True, True, False, True, True], color='red')    
#or as kwarg of len N 1
#ax.fill_between(theta, data1, data2, where=[True, True, False, True, True, True], color='red')

Output: