-------- back to fun signals and high school algebra during my psychosis i.e. one big long extended flashback, i often daydream of how you might upsample a signal from an extended recording, because i am trying to try it. i poked at a fourier transform by hand, without using visuals, again, and i am reminded that the indices in the fourier transform are the frequency, not the period, which means you get more fine detail at high frequencies when you take the fourier of lots of data. anyway, so, i guess this is obvious already, but i wonder if that means you could take a long recording of a repeating signal, and then take only the higher region of the fourier transform output, and then apply the ifft to that, to get an upsampled version. i'm guessing that this would roughly work, and the only reason i haven't done it in the past is because i didn't have enough computer ram to do a fourier that large, and wanted to understand it to take it apart manually. i'd like to test it! i'm thinking of generating some kind of high quality signal, and then repeating it, and sampling it at a lower and non-integral-multiple rate of the generated data, taking the fourier transform, and then reconstructing it. this may engage more triggers than i expect, but it sounds fun!