Python Forum - Sine fitting - extra modulation

Hi,
I have some issues with sine fitting, I use a very simple sine equation

y = a + b*np.sin(N_p*theta+c)

but the result gives me some kind of extra modulation on amplitude. Maybe someone has experienced a similar issue?

(Jan-03-2023, 01:33 PM)Pikano Wrote: [ -> ]but the result gives me some kind of extra modulation on amplitude.

Which code produced the chart?

(Jan-03-2023, 03:30 PM)Gribouillis Wrote: [ -> ]
(Jan-03-2023, 01:33 PM)Pikano Wrote: [ -> ]but the result gives me some kind of extra modulation on amplitude.
Which code produced the chart?