Fractional shift
Shift a signal by a (possibly fractional) number of samples.
fracshift(x, d, h = NULL)
x |
input data, specified as a numeric vector. |
d |
number of samples to shift |
h |
interpolator impulse response, specified as a numeric vector. If NULL (default), the interpolator is designed by a Kaiser-windowed sinecard. |
The function calculates the initial index and end index of the sequences of
1’s in the rows of x. The clusters are sought in the rows of the array
x. The function works by finding the indexes of jumps between
consecutive values in the rows of x.
A list of matrices size nr, where nr is the number of
rows in x. Each element of the list contains a matrix with two rows.
The first row is the initial index of a sequence of 1’s and the second row
is the end index of that sequence. If nr == 1 the output is a matrix
with two rows.
Eric Chassande-Mottin, ecm@apc.univ-paris7.fr,
Juan Pablo Carbajal, carbajal@ifi.uzh.ch,
Conversion to R by Geert van Boxtel, G.J.M.vanBoxtel@gmail.com.
[1] A. V. Oppenheim, R. W. Schafer and J. R. Buck,
Discrete-time signal processing, Signal processing series,
Prentice-Hall, 1999.
[2] T.I. Laakso, V. Valimaki, M. Karjalainen and U.K. Laine
Splitting the unit delay, IEEE Signal Processing Magazine,
vol. 13, no. 1, pp 30–59 Jan 1996.
N = 1024
t <- seq(0, 1, length.out = N)
x <- exp(-t^2 / 2 / 0.25^2) * sin(2 * pi * 10 * t)
dt <- 0.25
d <- dt / (t[2] - t[1])
y <- fracshift(x, d)
plot(t, x, type = "l", xlab = "Time", ylab = "Sigfnal")
lines (t, y, col = "red")
legend("topright", legend = c("original", "shifted"), lty = 1, col = 1:2)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.