TypeError: scipy/linalg/interface.py

[solomonvimal]

I'm getting an error if I use the fit function for the standard example. I'm using Python3.6 and scipy version 1.1.0.

my_pwlf = pwlf.PiecewiseLinFit(x, y)
res = my_pwlf.fit(2)

The error message is:
`
File "/home/svimal/miniconda3/lib/python3.6/site-packages/scipy/optimize/lbfgsb.py", line 378, in _minimize_lbfgsb
hess_inv = LbfgsInvHessProduct(s[:n_corrs], y[:n_corrs])
File "/home/svimal/miniconda3/lib/python3.6/site-packages/scipy/sparse/linalg/interface.py", line 144, in new
obj = super(LinearOperator, cls).new(cls)

TypeError: super(type, obj): obj must be an instance or subtype of type`

[cjekel]

Does this happen for any x and y data? If so it might be a problem with the lbfgsb in your scipy version.

Can you update scipy to version 1.2.0 and report back?

[solomonvimal]

@cjekel: Thanks! Yes, updating scipy (from 1.1.0 to 1.4.1) fixed the issue.