Hello folks,

I was happily testing the multiecho combine method, OC_tedort when I ran into an issue during the regression stage:

** ERROR: !! 3dDeconvolve: Can't run past 5 matrix warnings without '-GOFORIT 5'

which was new. I believe the only change was to apply motion regressors per run. The error itself comes from here,

++ Wrote matrix values to file X.nocensor.xmat.1D
*+ WARNING: -------------------------------------------------
*+ WARNING: Problems with the X matrix columns, listed below:
*+ WARNING: !! * Columns 107 [morts_r02[3]#0] and 208 [morts_r02[104]#0] are (nearly?) collinear!
*+ WARNING: !! * Columns 112 [morts_r02[8]#0] and 211 [morts_r02[107]#0] are (nearly?) collinear!
*+ WARNING: -------------------------------------------------

I investigated these multiecho derived orts (morts is a nice name) and they are not just nearly collinear, they are absolutely identical. This is both before and after projecting out the good components.

is it a problem with the (large) number of regressors leading to some strange wrap around? The first run did not report any problems, but had a smaller number of regressors.

Also, would this large number of regressors (203, but total timepoints = 890) be expected slow down the 3dREML voxel loop?

Thanks for the work on multiecho! Let me know if there are any particular details you would like to see.