How did scipy ver 0.18 scipy.interpolate.UnivariateSpline deal with values not strictly increasing?
IIRC this was whatever the FITPACK (the fortran library the univariatespline class wraps) was doing. So the first stop would be to remove the check from your local scipy install and see if this does the trick
I have a program written in python 2.7.5 scipy 0.18.1 that is able to run scipy.interpolate.UnivariateSpline with arrays that are non-sequential. When I try to run the same program in python 2.7.14 / scipy 1.0.0 I get the following error:
File "/usr/local/lib/python2.7/site-packages/scipy/interpolate/fitpack2.py", line 176, in init
    raise ValueError('x must be strictly increasing')
Usually I would just fix the arrays to remove the non-sequential values. But in this case I need to reproduce the exact same solution produced by the earlier version of python/scipy. Can anyone tell me how the earlier code dealt with the situation where the values were not sequential?