neuRosim (version 0.2-14)

lowfreqdrift: Generate low frequency drift

Description

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

Usage

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

Value

An array containing the drift with dimensions specified in dim.

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.

Author

Y. Rosseel, M. Welvaert

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.

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)
rm(d,freq,nscan,TR,out)