malib.py 文件源码

def contour_edges(a):
    import matplotlib.pyplot as plt
    a = checkma(a)
    #Contour nodata value
    levels = [a.fill_value]
    #kw = {'antialiased':True, 'colors':'r', 'linestyles':'-'}
    kw = {'antialiased':True}
    #Generate contours around nodata
    cs = plt.contour(a.filled(), levels, **kw)
    #This returns a list of numpy arrays
    #allpts = np.vstack(cs.allsegs[0])
    #Extract paths
    p = cs.collections[0].get_paths()
    #Sort by number of vertices in each path
    p_len = [i.vertices.shape[0] for i in p]
    p_sort = [x for (y,x) in sorted(zip(p_len,p), reverse=True)]    
    #cp = p[0].make_compound_path(*p)
    return p_sort

#Brute force search for edges of valid data