Would it make sense to have a maxlag keyword option on xcorr to limit how
big the lags it considers are?

On Friday, April 8, 2016, DNF <[email protected]> wrote:

> The xcorr function calls the conv function, which again uses fft. If you
> know the general structure and length of your signals ahead of time, you
> can probably gain some performance by planning the ffts beforehand. I don't
> know why it doesn't work for you, but you could have a look in at conv in
> dsp.jl.
>
> If you *really* want to speed things up, though, you might implement your
> own xcorr.  xcorr dominates the runtime in your function, and if you know
> an upper bound on the signal lags, you can implement xcorr with a limited
> number of lags. By default xcorr calculates for all lags (in your case
> that's 2*48000*60-1 ~ 6million lags). If you know that the max lag is 1
> second, you can save ~98% percent of the runtime of xcorr.
>
> A couple of other remarks:
> * There's no need to put type annotations next to the function outputs,
> it's just visual noise
> * Use ct_idx = cld(lₛ, 2) and forget about the mod.
>

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