mapsplot.py 文件源码

def polygons(latitudes, longitudes, clusters, maptype=MAPTYPE):
    """Plot clusters of points on map, including them in a polygon defining their convex hull.

    :param pandas.Series latitudes: series of sample latitudes
    :param pandas.Series longitudes: series of sample longitudes
    :param pandas.Series clusters: marker clusters, as integers
    :param string maptype: type of maps, see GoogleStaticMapsAPI docs for more info

    :return: None
    """
    width = SCALE * MAX_SIZE
    img, pixels = background_and_pixels(latitudes, longitudes, MAX_SIZE, maptype)

    polygons = []
    for c in clusters.unique():
        in_polygon = clusters == c
        if in_polygon.sum() < 3:
            print '[WARN] Cannot draw polygon for cluster {} - only {} samples.'.format(c, in_polygon.sum())
            continue
        cluster_pixels = pixels.loc[clusters == c]
        polygons.append(Polygon(cluster_pixels.iloc[ConvexHull(cluster_pixels).vertices], closed=True))

    plt.figure(figsize=(10, 10))
    ax = plt.subplot(111)
    plt.imshow(np.array(img))                                               # Background map
    p = PatchCollection(polygons, cmap='jet', alpha=0.15)                   # Collection of polygons
    p.set_array(clusters.unique())
    ax.add_collection(p)
    plt.scatter(                                                            # Scatter plot
        pixels['x_pixel'],
        pixels['y_pixel'],
        c=clusters,
        s=width / 40,
        linewidth=0,
        alpha=0.25,
    )
    plt.gca().invert_yaxis()                                                # Origin of map is upper left
    plt.axis([0, width, width, 0])                                          # Remove margin
    plt.axis('off')
    plt.tight_layout()
    plt.show()