Hi Doug,
I created a new first level analysis along with new contrasts and event numbers for a group of subjects I had previously done analyses on. All but one of the subjects finished selxavg3 without error, but one subject gave the following error:
Saving X matrix to /home/sidkundu/freesurfer/sessions/Heading-TTP/LMV2010_N19_Heading-TTP/bold/TTP-analysis-3/Xtmp.mat Error using svd Input to SVD must not contain NaN or Inf.
Error in cond (line 39) s = svd(A);
Error in fast_selxavg3 (line 248) XCond = cond(XtX);
ERROR: fast_selxavg3() failed\n
I looked at the generated Xtmp.mat file and it shows the design matrix X has all zeros in 2 columns, resulting in NaNs in the same columns for Xn, and corresponding NaNs in XtX. I'm wondering what would cause this or why it would only occur for only one subject.
_________________________________ Sid Kundu Biomedical Engineering Boston University