Tips and questions

[gacarita]

Hello there,

My name is Gabriel i wanna ask something here.

I'm using lombscargle periodogram to verify some frequencys in my orbits dynamics. I'm starting with a simple example a mean motion resonance 1:1.

In this case i'm getting what i want (1 period of peak). However if i follow the best fit frequency model described in the docs i have the result below.

I'm not sure if the fitting model is working very well for my model, there is something i could be doing wrong ? I would love some tips to help me understand this tool.

[giordano]

As explained in the documentation and on Wikipedia, the Lomb-Scargle periodogram uses functions of the type $a_{f} \cos(\omega t) + b_{f}\sin(\omega t) + c_{f}$. With a single frequency $f$ it's highly unlikely you'll be able to fit your data, unless it's purely a sum of a sine and a cosine of the same frequency. You can get better results by finding the next frequencies. The documentation has an example of using models with multiple frequencies, but in general Lomb-Scargle isn't for closely fitting completely arbitrary data, the main use case is for finding the main period.