如何使用 Matplotlib 在等高线图上设置更多自动级别？

Question

I am plotting the following picture

with the following code

plt.pcolormesh(ticks[0], ticks[2], np.transpose(potential), zorder=0)
plt.contour(ticks[0], ticks[2], np.transpose(potential), zorder=1, colors='black', linestyles='solid')
plt.pcolormesh(ticks[0], ticks[2], np.transpose(rectangle), cmap=ListedColormap([[1, 1, 1, 0], [0, 0, 0, 1]]), zorder=2)

Now I want more contour levels. If I code

plt.contour(ticks[0], ticks[2], np.transpose(potential), zorder=1, colors='black', linestyles='solid', levels=100)

(or any other integer) I get the warning

/opt/anaconda3/lib/python3.5/site-packages/matplotlib/contour.py:1180: UserWarning: No contour levels were found within the data range.

and picture without contour at all

How to overcome?

Answer 1

我要写

plt.contour(ticks[0], ticks[2], np.transpose(potential), 100, zorder=1, colors='black', linestyles='solid')