Matplotlib:AttributeError:“PolarAxesSubplot”对象没有属性“polar”

Question

我得画一个极坐标和一个散射点。代码如下：

fig = plt.figure()
ax = fig.add_subplot(1, 1, 1, projection='polar')

iterator = lidar.iter_scans()
line = ax.scatter([0, 0], [0, 0], s=5, color="xkcd:salmon")
ax.set_rmax(DMAX)
ax.grid(True)
data = []


def environment():
    for i, scan in enumerate(lidar.iter_scans(5000)):
        if i <= 100:
            if i > 2:
                data.extend(scan,)
        else:
            break

    lidar.stop()
    lidar.get_info()
    lidar.get_info()
    lidar.get_health()

env_variable= np.array([(np.radians(meas[1]), meas[2])
                        for meas in data])
theta= [eachValue[0] for eachValue in env_variable]

r= [eachValue[1] for eachValue in env_variable]

ax.polar(theta, r)   

最后一行(ax.polar(theta, r) )创建错误。如何在同一张图上画出这个极坐标，或者在同一个地方画两张图的最佳方法是什么