fit curve to oscillatory data

Question

Very Determined 2020-2-10

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/504750-fit-curve-to-oscillatory-data

回答： Very Determined 2020-2-12

Waves.xlsx

I have a set of data (an example is attached) and I want to fit the a specific curve and find a parameter. However, I am so new this this signal processing world and I am confused with the different terms and commands. I have this function

for one sinisoida wave where i is sqrt(-1); ω is angualr frequency; t is time and B and c are constatnts where B is not known. I imagine for a wave like what I have attached it should be

. Σ comes into play since the signal shape tells that it is a combination of sinosoidal waves otherwise there would be no Σ in the formula.

Anybody can help me doing this in order to find the right fit to the dat to find B ? (my understanding is that it might be

where Bj is connected to each wave that can perhaps be found using Fourier series; not sure anyway)

Thanks