The demeaning/mean centering worked a treat! Thank you freesurfer experts! 

Laura. 

On Thu, Mar 1, 2012 at 11:36 AM, Douglas N Greve <greve@nmr.mgh.harvard.edu> wrote:
If it's working with demeaning, then that was the problem. The subjects with NaNs are going to be excluded entirely as we have no way to estimate missing fields.
doug

Laura Tully wrote:
Hi Nick and Doug,
Thanks for the help, I'll give the demeaning a try.
Re: the missing values - all my missing data points are denoted with NaN so that I can include those subjects on the measures that they do have, but exclude them on measures they don't have (I think this is the only way to load the data table if there are missing values, is that correct?) This seems to be working fine when I do not include ICV as a nuisance variable. Do you think that these non-number cells are causing the issue? (I have check the data table to make sure that there are no empty cells).
Laura.
On Thu, Mar 1, 2012 at 11:14 AM, Douglas N Greve <greve@nmr.mgh.harvard.edu <mailto:greve@nmr.mgh.harvard.edu>> wrote:

   In the terminal output, it says that it will exclude a subject
   because there is a NaN data point. NaN = "not a number". Check
   your data table to make sure that everything is ok.
   doug


   Nick Schmansky wrote:

       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.laura@googlemail.com
           <mailto:tully.laura@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
           <http://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
                  <greve@nmr.mgh.harvard.edu
           <mailto:greve@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
                                                                     ltully@fas.harvard.edu <mailto:ltully@fas.harvard.edu>
                                  <mailto:ltully@fas.harvard.edu

           <mailto:ltully@fas.harvard.edu>>
                                                                                                        ------------------------------------------------------------------------
                                                                     _______________________________________________
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                                          --                 Douglas
           N. Greve, Ph.D.
                          MGH-NMR Center
                          greve@nmr.mgh.harvard.edu
           <mailto:greve@nmr.mgh.harvard.edu>
                          Phone Number: 617-724-2358
           <tel:617-724-2358> Fax: 617-726-7422 <tel:617-726-7422>
                                          Bugs:
           surfer.nmr.mgh.harvard.edu/fswiki/BugReporting
           <http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting>
                          FileDrop:
                                     www.nmr.mgh.harvard.edu/facility/filedrop/index.html
           <http://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
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                          contains patient information, please
           contact the
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                          http://www.partners.org/complianceline . If
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                                                          --                    Laura Tully
                  Social Neuroscience & Psychopathology
                  Harvard University
                  806 William James Hall
                  33 Kirkland St
                  Cambridge, MA 02138
                  ltully@fas.harvard.edu <mailto:ltully@fas.harvard.edu>
                          +1 857 207 5509 <tel:%2B1%20857%20207%205509>

                 


           --             Laura Tully
           Social Neuroscience & Psychopathology
           Harvard University
           840 William James Hall
           33 Kirkland St
           Cambridge, MA 02138
           ltully@fas.harvard.edu <mailto:ltully@fas.harvard.edu>




           _______________________________________________
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   --     Douglas N. Greve, Ph.D.
   MGH-NMR Center
   greve@nmr.mgh.harvard.edu <mailto:greve@nmr.mgh.harvard.edu>
   Phone Number: 617-724-2358 <tel:617-724-2358> Fax: 617-726-7422
   <tel:617-726-7422>

   Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting
   <http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting>
   FileDrop: www.nmr.mgh.harvard.edu/facility/filedrop/index.html
   <http://www.nmr.mgh.harvard.edu/facility/filedrop/index.html>





--
Laura Tully
Social Neuroscience & Psychopathology
Harvard University
840 William James Hall
33 Kirkland St
Cambridge, MA 02138
ltully@fas.harvard.edu <mailto:ltully@fas.harvard.edu>





--
Laura Tully
Social Neuroscience & Psychopathology
Harvard University
840 William James Hall
33 Kirkland St
Cambridge, MA 02138
ltully@fas.harvard.edu