Dear Freesurfer forum,
'I am trying to run qdec analysis for a group of subjects to see if correlation exists but I am getting this error only for this particular set of data but could not figure out what is exactly wrong with it. Your suggestion would be greatly appreciated.
Following is the terminal output for the process: .......... Saving design matrix to /g/f/h/s/freesurfer/subjects/qdec/Untitled/Xg.dat Normalized matrix condition is 27492.1 Design matrix ------------------ 1.000 0.408; 1.000 0.417; 1.000 0.417; 1.000 0.405; 1.000 0.412; 1.000 0.412; 1.000 0.411; 1.000 0.417; 1.000 0.405; 1.000 0.406; 1.000 0.402; 1.000 0.419; 1.000 0.413; 1.000 0.413; -------------------------------- ERROR: matrix is ill-conditioned or badly scaled, condno = 27492.1 -------------------------------- Possible problem with experimental design: Check for duplicate entries and/or lack of range of continuous variables within a class. If you seek help with this problem, make sure to send: 1. Your command line: mri_glmfit --y /g/f/h/s/freesurfer/subjects/qdec/Untitled/y.mgh --fsgd /g/f/h/s/freesurfer/subjects/qdec/Untitled/qdec.fsgd dods --glmdir /g/f/h/s/freesurfer/subjects/qdec/Untitled --surf fsaverage lh --label /g/f/h/s/freesurfer/subjects/fsaverage/label/lh.aparc.label --C /g/f/h/s/freesurfer/subjects/qdec/Untitled/contrasts/lh-Avg-Intercept-thickness.mat --C /g/f/h/s/freesurfer/subjects/qdec/Untitled/contrasts/lh-Avg-thickness-alpha1-Cor.mat 2. The FSGD file (if using one) 3. And the design matrix above Error in Analyze: command failed: mri_glmfit --y /g/f/h/s/freesurfer/subjects/qdec/Untitled/y.mgh --fsgd /g/f/h/s/freesurfer/subjects/qdec/Untitled/qdec.fsgd dods --glmdir /g/f/h/s/freesurfer/subjects/qdec/Untitled --surf fsaverage lh --label /g/f/h/s/freesurfer/subjects/fsaverage/label/lh.aparc.label --C /g/f/h/s/freesurfer/subjects/qdec/Untitled/contrasts/lh-Avg-Intercept-thickness.mat --C /g/f/h/s/freesurfer/subjects/qdec/Untitled/contrasts/lh-Avg-thickness-alpha1-Cor.mat
Many thanks in advance.
Regards, Nabin