scipy
numpy
nose
matplotlib
numpydoc
sympy
pandas
cython>=0.22
six
setuptools>=18.0
pyyaml

scipy
numpy
nose
matplotlib
numpydoc
sympy
pandas
cython>=0.22
six
setuptools>=18.0
pyyaml
xarray

Add xarray as requirement to build docs.
Add xarray as requirement to build docs.
