Hello,
I am trying to use the glm_fit to correlate a continuous variable (index) with cortical thickness, when controlling for age, education, and cognition (MMSE) (all continuous variables). However, I get the following error:
-------------------------------- ERROR: matrix is ill-conditioned or badly scaled, condno = 1e+08 -------------------------------- 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 lh.index.thickness.10.mgh --fsgd index.fsgd dods --C index.mtx --surf fsaverage lh --cortex --glmdir lh.index.glmdir 2. The FSGD file (if using one) 3. And the design matrix above Please find attached my fsgd file and the design matrix. I searched the archives and found out that a possible reason for this may be creating my file in Windows. Indeed, I created it by copy-pasting the data from an Excel spreadsheet into an empty txt file. I tried to convert it on Linux, using the command old.fsgd | sed 's/\r/\n/g' > new.fsgd, as well as making a new txt file on Linux (by copy -paste from a spreadsheet), but these did not work either. How can I solve this?
Thank you for the help!
Best, Teodora