How do i find the amplitude of a sine wave?

I have made a simulation in simulink which outputs a sine wave, i have plotted this sine wave in matlab but need to find the amplitude after a certain time.

[Akira Agata]

It depends on your data. Here are some possible solutions which have just came up in my mind:

• If your sinusoidal waveform is very clear, then simply measrue the peak-to-peak
• If slightly noisy, apply movmean or something, and then measure the peak-to-peak
• If more noisy, smoothening the data (ex. movmean), find several peaks and bottoms (findpeaks), and measure the average peak-to-peak
• If more noisy, smoothening, sinusoidal fitting ... etc might be needed

If possible, please upload your data so that many experts here in this community can try their idea.