Merge pull request #3 from roxyboy/print

made the mask argument compatible for POP

Merge pull request #2 from roxyboy/indexing

working faster on POP data now too

notebook working quicker with xarray.Variable

Sped up the code by using xarray.Variable for the index of da

Merge branch 'master' of github.com:roxyboy/xregrid

Edited notebooks for Python 3 compatibility

Merge pull request #1 from roxyboy/tests

additional fix for converting zip to list in python 3

zip does not return list in Python 3 so I added the argument

made args argument compatible with Python 3

added tests

got rid of ambiguous RuntimeError

removed spacing between codecov and travis