python - Clear overlay scatter on matplotlib image

Question

So I am back again with another silly question. Consider this piece of code

x = linspace(-10,10,100);
[X,Y]=meshgrid(x,x)
g = np.exp(-(square(X)+square(Y))/2)
plt.imshow(g)
scat = plt.scatter(50,50,c='r',marker='+')

Is there a way to clear only the scatter point on the graph without clearing all the image? In fact, I am writing a code where the appearance of the scatter point is bound with a Tkinter Checkbutton and I want it to appear/disappear when I click/unclick the button.

Thanks for your help!

Answer 1

的返回句柄plt.scatter有几种方法，包括remove(). 所以你需要做的就是调用它。用你的例子：

x = np.linspace(-10,10,100);
[X,Y] = np.meshgrid(x,x)
g = np.exp(-(np.square(X) + np.square(Y))/2)
im_handle = plt.imshow(g)
scat = plt.scatter(50,50,c='r', marker='+')
# image, with scatter point overlayed
scat.remove()
plt.draw()
# underlying image, no more scatter point(s) now shown

# For completeness, can also remove the other way around:
plt.clf()
im_handle = plt.imshow(g)
scat = plt.scatter(50,50,c='r', marker='+')
# image with both components
im_handle.remove()
plt.draw()
# now just the scatter points remain.

（几乎？）所有 matplotlib 渲染函数都返回一个句柄，它有一些方法可以删除渲染的项目。

请注意，您需要调用 redraw 以查看remove()-- 从删除帮助（我的重点）中的效果：

如果可能，将艺术家从图中移除。在重新绘制图形之前，效果将不可见，例如，使用 :meth: matplotlib.axes.Axes.draw_idle。