How do I calculate the frequency of the highest amplitude wave?
This shows the subset of the data you included and the absolute value of the DFT (discrete Fourier transform) of a zero-padded version of it.





R Code Below
    #Q31040

data &lt;- read.csv('Q31040/data.csv')

par(mfrow=c(2,1))
plot(data, type='l', col="blue")

zero_padded_data &lt;- c(data$Volts, rep(0,1000))

omega &lt;- seq(0,2*pi - 2*pi/length(zero_padded_data),2*pi/length(zero_padded_data))
fft_data &lt;- abs(fft(zero_padded_data))
plot(omega, fft_data, type='l', col="blue")

peak &lt;- which.max(fft_data)
points(omega[peak], fft_data[peak], col="red", lwd = 5)
title(paste("Peak location is", omega[peak]))