When I use mplot3D, why get error: NameError: name 'plot_trisurf' is not defined
<p>I try to use mplot3D to draw some 3D pictures: </p>

<pre><code>import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
...
plot_trisurf(X, Y, Z1)
</code></pre>

<p>Then my computer will tell me that </p>

<pre><code>NameError: name 'plot_trisurf' is not defined
</code></pre>

<p>Why this happen?  I thought I have imported it already.</p>