I know what I am attempting is not easy but I have a spectrum with peaks at 10Hz 20Hz and 30Hz. I also have various amplitudes at these peaks. I want to recreate my original signal. I initially thought this could be done by adding up sine waves
y(t) = a1sin(2*pi*ff1*t)+a2sin(4*pi*ff1*t)+a3sin(6*pi*ff1*t)
with a1 , a2 and a3 based on the amplitudes of the peaks however, When I recreate my time signal and so this in two axes the trace I get is not what I would expect, where am I going wrong?