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3

Based on the above referenced (and unreferenced) answers on mathematica.stackexchange, here is a short version of running code: data=Au4; (* input *) timeInterval = 10; (* input *) nSamples = Length@data; dt=timeInterval/nSamples; spectrumLength = Floor[0.5 nSamples]; powerSpectralDensity = Abs[Fourier[signal][[;; ...


6

You have to reverse all the steps you took, ifw = Chop@InverseFourier[fw, FourierParameters -> {1, 1}]; ifw = ifw*(-1)^Table[i + j, {i, nRow}, {j, nCol}]; idata = Map[{#, #, #} &, ifw, {2}]; GraphicsRow[{Image[idata], Image[data]}, ImageSize -> 800] I noticed that the three channels of your data aren't exactly equivalent, though they are for ...


3

We'll do this at a few different precisions. First we show the result from the original input and also from machine doubles created from that input. sd = Table[ AstronomicalData["Sun", {"Declination", DateList[t]}], {t, 3155716800, 3155716800 + 86400*365.2425*10, 86400}]; sdvals = sd[[All, 1]]; Max[Abs[Fourier[sdvals]]] Max[Abs[Fourier[N[sdvals]]]] ...



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