Centered autocorrelation (unnormalized)

Computes an unnormalized autocorrelation with zero lag at the center, equivalent to MATLAB xcorr(x).

Usage

autocorr_centered(x, method = c("auto", "direct", "fft"))

Arguments

x

numeric vector.

method

autocorrelation backend: "direct" (explicit summation), "fft" (FFT-based linear autocorrelation), or "auto" (uses "direct" for short vectors and "fft" for longer vectors).

Value

numeric vector of length 2*length(x) - 1.