[VoxBo] Adding derivativesin GDW error

[Dongbo Hu]

On Mon, 26 Mar 2007, Charan Ranganath wrote:

>_Dongbo, thanks for looking into this. We really would like to test out
>_this feature in order to see if using an informed basis set (HRF plus 2
>_derivatives) can help us deal with variability in BOLD responses.
>_

Charan, I have modified the code so that derivative operation is now
allowed if the number of elements in upsampled covariate is even. For
example, suppose the number of iamges in your data is 155 and TR is
2000ms, by default the upsampling rate is 100ms, so the number of points
in upsampled G matrix will be:

155 * 2000 / 100 = 3100

which is an even number and derivative is allowed. I hope this will be
helpful to you.

I am not sure whether you want to try this feature now or wait for our
next release. We probably will have a new release soon.

Dongbo