Description Usage Arguments Details Value Author(s) References Examples
Compute the ACF of a signal.
1 2 |
signal |
The signal, a numeric vector. |
lag.max |
The maximum lag value to be returned. |
window |
The type of window to be applied to the signal. Uses the windowfunc() function in this package. For no window select 'rectangular'. |
show |
If TRUE, the results are plotted. |
correct |
If TRUE, the output is corrected based on the window length and the window function that is applied. |
The autocorrelation function is calculated using the inverse Fourier transform applied to the power spectrum. This leads to much faster calculation times than the acf() function included in the typical R installation. Corrections for window type and length are carried out as described in Boersma (1993).
A dataframe with the following columns:
lag |
Indicates the lag value. |
acf |
Indicates the ACF value at the lag. |
Santiago Barreda <sbarreda@ucdavis.edu>
Boersma, P., (1993). Accurate short-term analysis of the fundamental frequency and the harmonics-to-noise ratio of a sampled sound. Proc. Instit. Phon. Sci. 17: 97-110.
1 2 3 4 5 6 7 8 9 10 | ## Uncomment and run the code below to see the speed advantage.
## Raising the n makes the difference even more pronounced.
#n = 25000
#system.time ({
#acf (rnorm (n), plot = F, lag.max = n)
#})
#system.time ({
#fastacf (rnorm (n), plot = F, lag.max = n)
#})
|
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