I'm attempting to debug a 3dMVM analysis. Ultimately, I want to do an analysis with two within-subject variables: load (0-back vs. 2-back in an Nback task) and valence (combat-related images vs. neutral images), and several between-subject quantitative regressors. But failing to get my script to run, for debugging purposes, I've removed the quantitative variables, reduced the number of subjects so I can more easily spot typos in the data table, and am attempting a very simple analysis with no GLTs.
Here's the current state of my debugging script:
3dMVM -prefix MVM_results \
-wsVars 'load*valence' \
-dataTable \
Subj load valence InputFile \
11917 0back combat stats.11917_resampled+tlrc.HEAD'[1]' \
11921 0back combat stats.11921_resampled+tlrc.HEAD'[1]' \
11922 0back combat stats.11922_resampled+tlrc.HEAD'[1]' \
11923 0back combat stats.11923_resampled+tlrc.HEAD'[1]' \
11924 0back combat stats.11924_resampled+tlrc.HEAD'[1]' \
11917 0back neutral stats.11917_resampled+tlrc.HEAD'[4]' \
11921 0back neutral stats.11921_resampled+tlrc.HEAD'[4]' \
11922 0back neutral stats.11922_resampled+tlrc.HEAD'[4]' \
11923 0back neutral stats.11923_resampled+tlrc.HEAD'[4]' \
11924 0back neutral stats.11924_resampled+tlrc.HEAD'[4]' \
11917 2back combat stats.11917_resampled+tlrc.HEAD'[7]' \
11921 2back combat stats.11921_resampled+tlrc.HEAD'[7]' \
11922 2back combat stats.11922_resampled+tlrc.HEAD'[7]' \
11923 2back combat stats.11923_resampled+tlrc.HEAD'[7]' \
11924 2back combat stats.11924_resampled+tlrc.HEAD'[7]' \
11917 2back neutral stats.11917_resampled+tlrc.HEAD'[10]' \
11921 2back neutral stats.11921_resampled+tlrc.HEAD'[10]' \
11922 2back neutral stats.11922_resampled+tlrc.HEAD'[10]' \
11923 2back neutral stats.11923_resampled+tlrc.HEAD'[10]' \
11924 2back neutral stats.11924_resampled+tlrc.HEAD'[10]'
No matter what I do, I get the same "Model test failed" error that isn't at all specific about what the issue is. Is there something obviously wrong with my syntax above?
Here's the feedback I get:
> more log
Package afex loaded successfully!
Package phia loaded successfully!
++++++++++++++++++++++++++++++++++++++++++++++++++++
***** Summary information of data structure *****
5 subjects : 11917 11921 11922 11923 11924
20 response values
2 levels for factor load : 0back 2back
2 levels for factor valence : combat neutral
0 post hoc tests
Contingency tables of subject distributions among the categorical variables:
valence
load combat neutral
0back 5 5
2back 5 5
Tabulation of subjects against each of the categorical variables:
~~~~~~~~~~~~~~
lop$nSubj vs load:
0back 2back
11917 2 2
11921 2 2
11922 2 2
11923 2 2
11924 2 2
~~~~~~~~~~~~~~
lop$nSubj vs valence:
combat neutral
11917 2 2
11921 2 2
11922 2 2
11923 2 2
11924 2 2
***** End of data structure information *****
++++++++++++++++++++++++++++++++++++++++++++++++++++
Reading input files now...
Reading input files: Done!
If the program hangs here for more than, for example, half an hour,
kill the process because the model specification or the GLT coding
is likely inappropriate.
~~~~~~~~~~~~~~~~~~~ Model test failed! ~~~~~~~~~~~~~~~~~~~
Possible reasons:
0) Make sure that R packages afex and phia have been installed. See the 3dMVM
help documentation for more details.
1) Inappropriate model specification with options -bsVars, -wsVars, or -qVars.
Note that within-subject or repeated-measures variables have to be declared
with -wsVars.
2) Incorrect specifications in general linear test coding with -gltCode.
3) Mistakes in data table. Check the data structure shown above, and verify
whether there are any inconsistencies.
4) Inconsistent variable names which are case sensitive. For example, factor
named Group in model specification and then listed as group in the table hader
would cause grief for 3dMVM.
5) Not enough number of subjects. This may happen when there are two or more
withi-subject factors. For example, a model with two within-subject factors with
m and n levels respectively requires more than (m-1)*(n-1) subjects to be able to
model the two-way interaction with the multivariate approach.
