lowfreqdrift: Generate low frequency drift

In NeuroStat/neuRosim: Functions to Generate fMRI Data Including Activated Data, Noise Data and Resting State Data

Description

Generates a low-frequency drift dataset with specified dimensions and frequency.

Usage

lowfreqdrift(dim, freq = 128, nscan, TR, template, verbose = TRUE)

Arguments

dim	A vector specifying the dimensions of the image.
freq	The frequency of the drift in seconds.
nscan	The number of scans in the dataset.
TR	The repetition time in seconds.
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 low-frequency drift based on a basis set of cosine functions. The result is an array with specified dimensions and frequency.

Value

An array containing the drift with dimensions specified in dim.

Author(s)

Y. Rosseel, M. Welvaert

References

Friston et al. (2007). Statistical Parametric Mapping: The analysis of functional brain images. Academic Press.

See Also

temporalnoise, systemnoise, physnoise, tasknoise, spatialnoise

Examples

d <- c(10,10,10)
freq <- 80
nscan <- 100
TR <- 2
out <- lowfreqdrift(d, freq, nscan, TR, verbose=FALSE)

NeuroStat/neuRosim documentation built on Sept. 14, 2019, 10:37 a.m.