fmri.detrend {fmri} | R Documentation |
Detrend fMRI dataset with a polynomial of given degree
fmri.detrend(data, degree = 1, accoef = 0)
data |
fMRI dataset of class ''fmridata '' |
degree |
Degree of the polynomial used to detrend the data. defaults to 1 (linear trends). |
accoef |
Coefficient of AR(1) model used for prewhitening. default 0. |
The function can be used to detrend the time series of an fMRI dataset data
(of class ''fmridata
'' using polynomials. If the argument degree
is larger than 0 (default: 1) the polynomial trends up to the given degree are removed from the data. If the argument accoef
is larger than 0 (default: 0) prewhitening using an AR(1) model is performed.
Detrended data object of class ''fmridata
''.
Joerg Polzehl polzehl@wias-berlin.de
Polzehl, J. and Tabelow, K. (2007). fmri: A Package for Analyzing fmri Data, R News, 7:13-17.
# Example 1 data <- list(ttt=writeBin(rnorm(32*32*32*107),raw(),4), mask=array(1,c(32,32,32)),dim=c(32,32,32,107)) class(data) <- "fmridata" data <- fmri.detrend(data,2)