Weird plots from running tuning curve fitting

[hummuscience]

I am fairly new to tuning curves and decoding and I wanted to try out spykes.

When I plot the fits, the curves are not aligned with the data. The first seem to assume an x-axis starting at 0 while the data is 25-41. Is it assumed that the x-variable has to be scaled before use? Somehow the x-axis is always labelled with radians as if it is hard-coded.

I put the data including the ipynb notebook I used in a ZIP archive:
tuning.zip

I ran it again, with scaling the x-varible, things are looking better, plot-wise but I am not sure the fit is working well.

It might be that I have too little data to calculate tuning curves (deconvoluted calcium traces)