| physnoise {neuRosim} | R Documentation |
Generate physiological noise
Description
Generates a physiological noise dataset with specified dimensions and standard deviation. The physiological noise is defined as noise caused by heart beat and respiratory rate.
Usage
physnoise(dim, nscan, TR, sigma, freq.heart = 1.17,
freq.resp = 0.2, template, verbose = TRUE)
Arguments
dim |
A vector specifying the dimensions of the image. |
nscan |
The number of scans in the dataset. |
TR |
The repetition time in seconds. |
sigma |
The standard deviation of the noise. |
freq.heart |
The frequency in Hz of the heart beat. |
freq.resp |
The frequency in Hz of the respiratory rate. |
template |
An array representing the anatomical structure or mask with dimensions equal to dim. |
verbose |
Logical indicating if warnings should be printed. |
Details
The function generates physiological noise. Heart beat and respiratory rate are defined as sine and cosine functions with specified frequencies. Additional Gaussian noise creates variability over voxels. The result is a noise dataset with specified dimensions and desired standard deviation.
Value
An array containing the noise with dimensions specified in dim and nscan.
Author(s)
M. Welvaert
See Also
temporalnoise, lowfreqdrift, systemnoise, tasknoise, spatialnoise
Examples
d <- c(10,10,10)
sigma <- 5
nscan <- 100
TR <- 2
out <- physnoise(d, nscan, TR, sigma, verbose=FALSE)