| block_rms {tagtools} | R Documentation |
Compute RMS of sample blocks
Description
This function is used to compute the RMS (root-mean-square) of successive blocks of samples.
Usage
block_rms(X, n, nov = NULL)
Arguments
X |
A vector or a matrix containing samples of a signal in each column. |
n |
The number of samples from X to use in each analysis block. |
nov |
The number of samples that the next block overlaps the previous block. |
Value
A list with 2 elements:
Y: A vector or matrix containing the RMS value of each block. If X is a mxn matrix, Y is pxn where p is the number of complete n-length blocks with nov that can be made out of m samples, i.e., n+(p-1)*(n-nov) < m
samples: The time at which each output in Y is reported, in units of samples of X. So if samples[1] = 12, then the value Y[1] corresponds to the “time” 12 samples in X. The times at which Y values are reported are the centers of the averaging windows.
Note
Output sampling rate is the same as the input sampling rate so s and v have the same size as p.
Frame: This function assumes a [north,east,up] navigation frame and a [forward,right,up] local frame. In these frames, a positive pitch angle is an anti-clockwise rotation around the y-axis. A descending animal will have a negative pitch angle.
Examples
X <- matrix(c(1:20), byrow = TRUE, nrow = 4)
block_rms(X, n = 2, nov = NULL)