Hi to all, I have been having troubles with qdec and several error messages appear. The first message appeared when clicking 'analyze'. It doesn't matter if i use one or two discrete plus one or two continuos factors, i get the same error message. What does it mean by codno=1e+08?
Creating output directory /Applications/freesurfer/subjects/qdec/ lh_postcentral_thickness
Loading y from /Applications/freesurfer/subjects/qdec/ lh_postcentral_thickness/y.mgh
Matrix condition is 1e+08
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.
Another error message that appeared earlier when i include age, gender, diagnosis(epilepsy/nonepileptic) and ln_postcentral_thickness is as follow:
$Id: mri_glmfit.c,v 1.138.2.3 2008/08/27 13:33:05 greve Exp $
cwd /Applications/freesurfer
cmdline mri_glmfit --y /Applications/freesurfer/subjects/qdec/ lh_postcentral_thickness/y.mgh --fsgd /Applications/freesurfer/ subjects/qdec/lh_postcentral_thickness/qdec.fsgd dods --glmdir / Applications/freesurfer/subjects/qdec/lh_postcentral_thickness --surf fsaverage lh --label /Applications/freesurfer/subjects/fsaverage/label/ lh.cortex.label --C /Applications/freesurfer/subjects/qdec/ lh_postcentral_thickness/contrasts/lh-Avg-Intercept-thickness.mat --C / Applications/freesurfer/subjects/qdec/lh_postcentral_thickness/ contrasts/lh-Avg-thickness-age-Cor.mat --C /Applications/freesurfer/ subjects/qdec/lh_postcentral_thickness/contrasts/lh-Avg-thickness- lh_postcentral_thickness-Cor.mat --C /Applications/freesurfer/subjects/ qdec/lh_postcentral_thickness/contrasts/lh-Diff-Male-Female-Intercept- thickness.mat --C /Applications/freesurfer/subjects/qdec/ lh_postcentral_thickness/contrasts/lh-Diff-Male-Female-Cor-thickness- age.mat --C /Applications/freesurfer/subjects/qdec/ lh_postcentral_thickness/contrasts/lh-Diff-Male-Female-Cor-thickness- lh_postcentral_thickness.mat --C /Applications/freesurfer/subjects/ qdec/lh_postcentral_thickness/contrasts/lh-Diff-nonepileptic-epilepsy- Intercept-thickness.mat --C /Applications/freesurfer/subjects/qdec/ lh_postcentral_thickness/contrasts/lh-Diff-nonepileptic-epilepsy-Cor- thickness-age.mat --C /Applications/freesurfer/subjects/qdec/ lh_postcentral_thickness/contrasts/lh-Diff-nonepileptic-epilepsy-Cor- thickness-lh_postcentral_thickness.mat --C /Applications/freesurfer/ subjects/qdec/lh_postcentral_thickness/contrasts/lh-X-gender-diagnosis- Intercept-thickness.mat --C /Applications/freesurfer/subjects/qdec/ lh_postcentral_thicknesss/contrasts/lh-X-gender-diagnosis-Cor- thickness-age.mat --C /Applications/freesurfer/subjects/qdec/ lh_postcentral_thickness/contrasts/lh-X-gender-diagnosis-Cor-thickness- lh_postcentral_thickness.mat
Can the above error occur because one of the two groups has only one subject (epilepsy and female). I have also attached fsgd1 generated by freesurfer as below:
GroupDescriptorFile 1
Title lh_postcentral_thickness
MeasurementName thickness
Class genderMale-diagnosisnonepileptic
Class genderFemale-diagnosisnonepileptic
Class genderMale-diagnosisepilepsy
Class genderFemale-diagnosisepilepsy
Variables age lh_postcentral_thickness
Input RCoward genderMale-diagnosisnonepileptic 11.000000 2.112000
Input SCoward genderFemale-diagnosisnonepileptic 13.000000 1.979000
Input JConigrave genderMale-diagnosisnonepileptic 10.000000 2.470000
Input AConigrave genderFemale-diagnosisnonepileptic 5.000000 2.268000
Input KBleasel genderFemale-diagnosisnonepileptic 9.000000 2.292000
Input MBleasel genderFemale-diagnosisnonepileptic 16.000000 2.181000
Input CMcintosh genderFemale-diagnosisnonepileptic 15.000000 2.107000
Input OJohanssen genderMale-diagnosisnonepileptic 6.000000 2.033000
Input MJohanssen genderFemale-diagnosisnonepileptic 6.000000 2.037000
Input GHerbert genderFemale-diagnosisnonepileptic 4.000000 2.209000
Input JRathmell genderMale-diagnosisnonepileptic 11.000000 2.287000
Input ARathmell genderMale-diagnosisnonepileptic 14.000000 2.223000
Input ZTucker genderFemale-diagnosisepilepsy 11.000000 2.415000
Your advice and tips will be most appreciated!
Toh Wong (Sydney, Australia)