"""
===========================================================
Plot contour (level) curves in 3D using the extend3d option
===========================================================

This modification of the :doc:`contour3d` example uses ``extend3d=True`` to
extend the curves vertically into 'ribbons'.
"""

import matplotlib.pyplot as plt

from matplotlib import cm
from mpl_toolkits.mplot3d import axes3d

ax = plt.figure().add_subplot(projection='3d')
X, Y, Z = axes3d.get_test_data(0.05)
ax.contour(X, Y, Z, extend3d=True, cmap=cm.coolwarm)

plt.show()

# %%
# .. tags::
#    plot-type: 3D,
#    level: beginner