I just installed matplotlib and am trying to run one of there example scripts. However I run into the error detailed below. What am I doing wrong?

```
from mpl_toolkits.mplot3d import axes3d
import matplotlib.pyplot as plt
fig = plt.figure()
ax = fig.gca(projection='3d')
X, Y, Z = axes3d.get_test_data(0.05)
cset = ax.contour(X, Y, Z, 16, extend3d=True)
ax.clabel(cset, fontsize=9, inline=1)
plt.show()
```

The error is

```
Traceback (most recent call last):
File "<string>", line 245, in run_nodebug
File "<module1>", line 5, in <module>
File "C:\Python26\lib\site-packages\matplotlib\figure.py", line 945, in gca
return self.add_subplot(111, **kwargs)
File "C:\Python26\lib\site-packages\matplotlib\figure.py", line 677, in add_subplot
projection_class = get_projection_class(projection)
File "C:\Python26\lib\site-packages\matplotlib\projections\__init__.py", line 61, in get_projection_class
raise ValueError("Unknown projection '%s'" % projection)
ValueError: Unknown projection '3d'
```

First off, I think `mplot3D`

worked a bit differently in `matplotlib`

version `0.99`

than it does in the current version of `matplotlib`

.

Which version are you using? (Try running: `python -c 'import matplotlib; print matplotlib."__version__")`

I'm guessing you're running version `0.99`

, in which case you'll need to either use a slightly different syntax or update to a more recent version of `matplotlib`

.

If you're running version `0.99`

, try doing this instead of using using the `projection`

keyword argument:

```
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import axes3d, Axes3D #<-- Note the capitalization!
fig = plt.figure()
ax = Axes3D(fig) #<-- Note the difference from your original code...
X, Y, Z = axes3d.get_test_data(0.05)
cset = ax.contour(X, Y, Z, 16, extend3d=True)
ax.clabel(cset, fontsize=9, inline=1)
plt.show()
```

This should work in `matplotlib`

`1.0.x`

, as well, not just `0.99`

.

Just to add to Joe Kington's answer (not enough reputation for a comment) there is a good example of mixing 2d and 3d plots in the documentation at http://matplotlib.org/examples/mplot3d/mixed_subplots_demo.html which shows projection='3d' working in combination with the Axes3D import.

```
from mpl_toolkits.mplot3d import Axes3D
...
ax = fig.add_subplot(2, 1, 1)
...
ax = fig.add_subplot(2, 1, 2, projection='3d')
```

In fact as long as the Axes3D import is present the line

```
from mpl_toolkits.mplot3d import Axes3D
...
ax = fig.gca(projection='3d')
```

as used by the OP also works. (checked with matplotlib version 1.3.1)

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