When I use the function clabel, I receive the warning:

/usr/lib/pymodules/python2.7/matplotlib/contour.py:486: DeprecationWarning: using a
non-integer number instead of an integer will result in an error in the future
nlc.append(np.r_[xy2, lc[I[1]:]])

The problem is that the array index I in lc[I[1]:]] is a float not an integer. The current code is

        # Make integer
        I = [np.floor(I[0]), np.ceil(I[1])]

Unfortunately, floor and ceil return floats rather than integers. I suggest converting I to integers, if possible (need to take care, make sure we don't do int(nan))

        # Make integer
        I = [np.floor(I[0]), np.ceil(I[1])]
        I = [ int(i) if not np.isnan(i) else i for i in I ]

or something similar - is there a way to make floor and ceil return integers? If not, maybe this will do.