Installing scikit-learn on Ubuntu is easy and straightforward. You can install it either using apt-get install or pip.

Here is the command to install scikit-learn using apt-get install:

    $ sudo apt-get install python-sklearn

We can install it using pip using the following command:

    $ sudo pip install scikit-learn

After installing scikit-learn, we can test the installation by doing following commands in Python Terminal.

>>> import sklearn 
>>> sklearn.__version__ 
'0.17' 

Congratulations, you have successfully set up scikit-learn!