it means to subtract the mean of the icv values from each. that way the values are close to zero, and closer in value to the other values in the glm (which seems to make the glm happier).
n. On Thu, 2012-03-01 at 11:04 -0500, Laura Tully wrote: > Hi Doug, > > > I saw on a previous mailing earlier this week that someone has been > having a similar error and that your advice was to demean the ICV. I > apologise if this is a stupid question, but what does it mean to > "demean"? And, how do i do that? > > > Thanks in advance! > > > Laura. > > On Wed, Feb 29, 2012 at 2:27 PM, Laura Tully > <tully.la...@googlemail.com> wrote: > Hi Doug, > > Below is the output in the terminal window from running the > analysis to the crash. Attached are the qdec.fsgd and y.fsgd > files from the qdec output. I'm not actually sure what these > file represent - could you enlighten me? > > Thanks! > Laura. > > > Number of subjects: 55 > Number of factors: 48 (2 discrete, 46 continuous) > Number of classes: 4 > Number of regressors: 188 > ============================================================ > > WARNING: will exclude subject 27115 from analysis due to NaN > data point! > > WARNING: will exclude subject 27211 from analysis due to NaN > data point! > > WARNING: will exclude subject 27212 from analysis due to NaN > data point! > lh-Avg-Intercept-thickness ----------------------- > Does the average thickness differ from zero? > Nuisance factors: IntraCranialVol > 1.000 1.000 0.000 0.000 0.000 0.000; > > lh-Avg-thickness-CPT_IP-Cor ----------------------- > Does the correlation between thickness and CPT_IP, accounting > for group, differ from zero? > Nuisance factors: IntraCranialVol > 0.000 0.000 1.000 1.000 0.000 0.000; > > lh-Diff-HC-SZ-Intercept-thickness ----------------------- > Does the average thickness differ between HC and SZ? > Nuisance factors: IntraCranialVol > 1.000 -1.000 0.000 0.000 0.000 0.000; > > lh-Diff-HC-SZ-Cor-thickness-CPT_IP ----------------------- > Does the thickness--CPT_IP correlation differ between HC and > SZ? > Nuisance factors: IntraCranialVol > 0.000 0.000 1.000 -1.000 0.000 0.000; > > ninputs = 52 > Checking inputs > nframestot = 52 > Allocing output > Done allocing > nframes = 52 > Writing > to > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/y.mgh > gdfReadHeader: > reading > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/qdec.fsgd > INFO: DeMeanFlag keyword not found, DeMeaning will NOT be > done. > Continuous Variable Means (all subjects) > 0 CPT_IP 2.83135 0.695203 > 1 IntraCranialVol 1.29955e+06 249396 > Class Means of each Continuous Variable > 1 groupHC 3.0515 1340186.4398 > 2 groupSZ 2.5936 1255661.8075 > INFO: gd2mtx_method is dods > Reading source > surface /ncf/snp/04/SCORE/freesurfer_analysis/fsaverage/surf/lh.white > Number of vertices 163842 > Number of faces 327680 > Total area 65416.648438 > AvgVtxArea 0.399267 > AvgVtxDist 0.721953 > StdVtxDist 0.195470 > > $Id: mri_glmfit.c,v 1.196.2.6 2011/05/05 20:54:25 greve Exp $ > cwd /ncf/snp/04/SCORE/freesurfer_analysis/qdec > cmdline mri_glmfit > --y > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/y.mgh > --fsgd > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/qdec.fsgd > dods --glmdir > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV --surf > fsaverage lh --label > /ncf/snp/04/SCORE/freesurfer_analysis/fsaverage/label/lh.aparc.label --C > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/contrasts/lh-Avg-Intercept-thickness.mat > --C > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/contrasts/lh-Avg-thickness-CPT_IP-Cor.mat > --C > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/contrasts/lh-Diff-HC-SZ-Intercept-thickness.mat > --C > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/contrasts/lh-Diff-HC-SZ-Cor-thickness-CPT_IP.mat > > sysname Linux > hostname ncfws17.rc.fas.harvard.edu > machine x86_64 > user ltully > FixVertexAreaFlag = 1 > UseMaskWithSmoothing 1 > OneSampleGroupMean 0 > y > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/y.mgh > logyflag 0 > usedti 0 > FSGD > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/qdec.fsgd > labelmask > /ncf/snp/04/SCORE/freesurfer_analysis/fsaverage/label/lh.aparc.label > maskinv 0 > glmdir > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV > IllCondOK 0 > ReScaleX 1 > DoFFx 0 > Creating output > directory > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV > Loading y > from > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/y.mgh > INFO: gd2mtx_method is dods > Saving design matrix > to > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/Xg.dat > Normalized matrix condition is 263.453 > Matrix condition is 1e+08 > Found 148151 points in label. > Pruning voxels by thr: 0.000000 > Found 148025 voxels in mask > Saving mask > to > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/mask.mgh > Reshaping mriglm->mask... > search space = 73649.347769 > DOF = 46 > Starting fit and test > Fit completed in 0.11535 minutes > Computing spatial AR1 on surface > Residual: ar1mn=0.996105, ar1std=0.001362, gstd=6.478212, > fwhm=15.255024 > Writing results > lh-Avg-Intercept-thickness > maxvox sig=21.5032 F=315.736 at index 99361 0 0 > seed=1330929601 > lh-Avg-thickness-CPT_IP-Cor > maxvox sig=3.23567 F=13.661 at index 155907 0 0 > seed=1330929601 > lh-Diff-HC-SZ-Intercept-thickness > maxvox sig=-2.63051 F=10.3802 at index 6941 0 0 > seed=1330929601 > lh-Diff-HC-SZ-Cor-thickness-CPT_IP > maxvox sig=-3.05362 F=12.6489 at index 145301 0 0 > seed=1330929601 > mri_glmfit done > ninputs = 4 > Checking inputs > nframestot = 4 > Allocing output > Done allocing > nframes = 4 > Writing > to > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/contrasts.sig.mgh > reading colortable from annotation file... > colortable with 36 entries read > (originally > /autofs/space/terrier_001/users/nicks/freesurfer/average/colortable_desikan_killiany.txt) > reading colortable from annotation file... > colortable with 36 entries read > (originally > /autofs/space/terrier_001/users/nicks/freesurfer/average/colortable_desikan_killiany.txt) > gdfReadHeader: > reading > /ncf/snp/04/SCORE/freesurfer_analysis/qdec/lh_thick_10mm_groupCPT_ICV/y.fsgd > INFO: ignoring tag Creator > INFO: ignoring tag SUBJECTS_DIR > INFO: ignoring tag SynthSeed > INFO: NOT demeaning continuous variables > Continuous Variable Means (all subjects) > 0 CPT_IP 2.83135 0.695203 > 1 IntraCranialVol 1.29955e+06 249396 > Class Means of each Continuous Variable > 1 groupHC 3.0515 1340187.1111 > 2 groupSZ 2.5936 1255662.3200 > MatrixMultiply: m1 is null! > > No such file or directory > > > > On Tue, Feb 28, 2012 at 5:51 PM, Douglas N Greve > <gr...@nmr.mgh.harvard.edu> wrote: > Can you send the fsgd file that is created? Also, > please send more text output. It's hard to tell from a > single line. > doug > > Laura Tully wrote: > Hi, > I am trying to run a between group analysis in > QDEC whilst controlling for intrancranial > volume. The design has one dichotomous > variable (group2, group2), one continuous > (performance on behavioral task), and one > nuisance variable (intracranial volume). each > time I run it qec crashes with the following > error: > MatrixMultiply: ml null! > > What does this error mean and how can I fix > it? > What is odd is that this error does not seem > to be consistently reproducible - after > successfully running the analyses without > controlling for ICV, I was then able to run it > with ICV as a nuisance factor. > Thank you! > Laura. > -- > Laura Tully > Social Neuroscience & Psychopathology > Harvard University > 806 William James Hall > 33 Kirkland St > Cambridge, MA 02138 > > ltu...@fas.harvard.edu > <mailto:ltu...@fas.harvard.edu> > > > > ------------------------------------------------------------------------ > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > -- > Douglas N. Greve, Ph.D. > MGH-NMR Center > gr...@nmr.mgh.harvard.edu > Phone Number: 617-724-2358 Fax: 617-726-7422 > > Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting > FileDrop: > www.nmr.mgh.harvard.edu/facility/filedrop/index.html > > > > The information in this e-mail is intended only for > the person to whom it is > addressed. If you believe this e-mail was sent to you > in error and the e-mail > contains patient information, please contact the > Partners Compliance HelpLine at > http://www.partners.org/complianceline . If the e-mail > was sent to you in error > but does not contain patient information, please > contact the sender and properly > dispose of the e-mail. > > > > > -- > Laura Tully > Social Neuroscience & Psychopathology > Harvard University > 806 William James Hall > 33 Kirkland St > Cambridge, MA 02138 > ltu...@fas.harvard.edu > > +1 857 207 5509 > > > > > > -- > Laura Tully > Social Neuroscience & Psychopathology > Harvard University > 840 William James Hall > 33 Kirkland St > Cambridge, MA 02138 > ltu...@fas.harvard.edu > > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
