downsample {gsignal}

Decrease sample rate

Description

Downsample a signal by an integer factor.

Usage

downsample(x, n, phase = 0)

Arguments

x

input data, specified as a numeric vector or matrix. In case of a vector it represents a single signal; in case of a matrix each column is a signal.

n

downsampling factor, specified as a positive integer.

phase

offset, specified as a positive integer from 0 to n - 1. Default: 0.

Details

For most signals you will want to use decimate instead since it prefilters the high frequency components of the signal and avoids aliasing effects.

Value

Downsampled signal, returned as a vector or matrix.

Author(s)

Paul Kienzle, [e-mail].
Conversion to R by Geert van Boxtel, [e-mail].

See Also

decimate, resample

Examples

x <- seq_len(10)
xd <- downsample(x, 3)     # returns 1  4  7 10
xd <- downsample(x, 3, 2)  # returns 3 6 9

x <- matrix(seq_len(12), 4, 3, byrow = TRUE)
xd <- downsample(x, 3)