How to add Python virtualenv to IPython Jupyter notebook

1)
Install jupyter
$pip install -U jupyter

2)
Create virtual environment
$virtualenv myenv1

3)
Activate virtual environment
$source myenv1/bin/activate

4)
Install ipykernel in virtual environment
$ pip install ipykernel

5)
Add python and ipykernel in the virtual environment to jupyter notebook
$ python -m ipykernel install --user --name=myenv1

You should now be able to see your (virtualenv) kernel in the IPython
notebook menu: Kernel -> Change kernel and be able so switch to it.