len=length(signal);
fs=50 % assuming you know the sampling frequency of your signal
n=0:len-1;
N=n*fs/(len-1); % convert x-axis in actual frequency
y=fft(signal);
plot(N,abs(y));
from the plot you can determine the frequency peak. I do not know any function for amplitude estimation. If the signal relatively low noisy, then (max(signal)-min(signal))/2 should give a rough estimate
