For an analyze .img file the periodogram of the time series are divided by a flat spectral estimate using the median periodogram ordinate. The resulting values are then combined within each Fourier frequency and quantiles are plotted against frequency. This provides a fast look at a fMRI dataset to identify any artifacts that reside at single frequencies.
f.spectral.summary(file, mask.file, ret.flag=FALSE)file The location of .img file
mask.file Optional location of a .img file
containing a mask. If not given then one is created.
ret.flag flag specifying whether to return the
array of quantiles at each frequency
If ret.flag = TRUE the an array of quantiles at each
frequency is returned