It is probably a scaling problem with using age^2. Try normalizing the age^2 column (ie, remove the mean and divide by the sum of the squares)
On 3/9/2023 3:30 PM, Triebswetter, Curtis wrote:
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Hello Freesurfer experts,
I am attempting to run the command
mri_glmfit --y lh.RBS_ADRC_N0_control.10.mgh --fsgd RBS_ADRC_APOE_age22.fsgd dods --C APOE_ageINT.mtx --surf fsaverage lh --cortex --glmdir lh.RBS_ADRC_N0.glmdir
On this .fsgd file:
“RBS_ADRC_APOE_age22.txt”
Using the following design matrix:
“lh.RBS_ADRC_N0.txt”
I am receiving the error message:
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.
I would appreciate your insights into what may be the likely cause of this error and apologize that the files are in text format. If need be, I can convert these to their proper formats.
misc information:
Freesurfer 6.00
CentOS v7
Best,
Curtis
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