create a function from temperature data

I have dataset from temperature and i would like to create a trignometric function to describe daily temperature variation. Is it possible?

Answer 1

[KSSV]

Read about interpft

Answer 2

[Walter Roberson]

If you have the Curve Fitting Toolbox, you can use curvefitter() https://www.mathworks.com/help/curvefit/curvefitter-app.html . Or for before R2022a use cftool() . You would select "Sum of sine" and 1 term. This would fit your data as a single sine wave with some amplitude, some frequency, and some phase offset.

If you do not have the Curve Fitting Toolbox, you could also use fft() and pick out the largest peak; the location would tell you the primary frequency, and the magnitude and imaginary component there would estimate the amplitude and the phase (but you would have to go back and recompute those to take into account the other frequencies.)

Answer 3

[Star Strider]

Another option: Curve fitting to a sinusoidal function