Hello SPM experts,
I'm running a flexible factorial design with a library of PET scans. My design will set up properly, however when I attempt to estimate the model sometimes I get the error message
Warning: Matrix is close to singular or badly scaled.
Results may be inaccurate. RCOND = -1.000000e+00.
> In spm_inv at 22
In spm_reml at 119
In spm_spm at 860
In spm_getSPM at 235
In spm_results_ui at 263
And this message will repeat dozens of times. When I remove a few subjects, the problem typically resolves. Can anybody tell me what might be the issue with the scans that are causing this problem?