Hi,

Out of interest, how exactly are bandpass regressors specified in 3dTproject? There is no option to output the design matrix, so I can't see.

However, when I attempt to define the regressors myself and then use the -ort option, I get results that are similar, but not as smooth as when using the -bandpass fbot ftop option (see attached, my attempt in red).

With N (even number) data points [0..N-1] I specify N/2 cosine regressors and (N/2)-1 sine regressors

cos(2*pi*f*[0..N-1]) and sin(2*pi*f*[0..N-1])

where f={1,2,..round(fbot*TR*N),round(ftop*TR*N),...N/2) for cosine and f={1,2,..round(fbot*TR*N),round(ftop*TR*N),..N/2-1} for sine.

Perhaps this is a naive way to do it, as it doesn't give as smooth results, and I'm not sure how to deal with an odd number of data points.

Any information would be appreciated!

Thanks

Joe