This program performs three-factor ANOVA on 3D data sets.
Usage: 3dANOVA3
-alevels a a = number of levels of factor A
-blevels b b = number of levels of factor B
-clevels c c = number of levels of factor C
and level 1 of factor B and level 1 of factor C
. . . . . .
and level j of factor B and level k of factor C
. . . . . .
[-voxel num] screen output for voxel # num
[-fa prefix] F-statistic for factor A effect
[-fb prefix] F-statistic for factor B effect
[-fc prefix] F-statistic for factor C effect
[-fab prefix] F-statistic for A*B interaction
[-fac prefix] F-statistic for A*C interaction
[-fbc prefix] F-statistic for B*C interaction
[-fabc prefix] F-statistic for A*B*C interaction
[-amean i prefix] estimate of factor A level i mean
[-bmean i prefix] estimate of factor B level i mean
[-cmean i prefix] estimate of factor C level i mean
The following command generates one AFNI ‘bucket’ type dataset:
Modified ANOVA computation options: (December, 2005)
- ** These options apply to model types 4 and 5, only.
- For details, see http://afni.nimh.nih.gov/sscc/gangc/ANOVA_Mod.html
[-assume_sph] assume sphericity (zero-sum contrasts, only)
This allows use of the old_method for computing contrasts which sum to zero (this includes diffs, for instance). Any contrast that does not sum to zero is invalid, and cannot be used with this option (such as ameans).
- Note: factor C is really subject within gender (since it is
- nested). There are 4 subjects in this example, and 2 subjects per gender. So clevels is 2.
- 3dANOVA3 -type 5
- -alevels 2 -blevels 3 -clevels 2 -dset 1 1 1 man1_houses+tlrc -dset 1 2 1 man1_faces+tlrc -dset 1 3 1 man1_donuts+tlrc -dset 1 1 2 man2_houses+tlrc -dset 1 2 2 man2_faces+tlrc -dset 1 3 2 man2_donuts+tlrc -dset 2 1 1 woman1_houses+tlrc -dset 2 2 1 woman1_faces+tlrc -dset 2 3 1 woman1_donuts+tlrc -dset 2 1 2 woman2_houses+tlrc -dset 2 2 2 woman2_faces+tlrc -dset 2 3 2 woman2_donuts+tlrc -adiff 1 2 MvsW -bdiff 2 3 FvsD -bcontr -0.5 1 -0.5 FvsHD -aBcontr 1 -1 : 1 MHvsWH -aBdiff 1 2 : 1 same_as_MHvsWH -Abcontr 2 : 0 1 -1 WFvsWD -Abdiff 2 : 2 3 same_as_WFvsWD -Abcontr 2 : 1 7 -4.2 goofy_example -bucket donut_anova
This program accepts datasets that are modified on input according to the following schemes:
‘r1+orig[3..5]’ {sub-brick selector} ‘r1+orig<100..200>’ {sub-range selector} ‘r1+orig[3..5]<100..200>’ {both selectors} ‘3dcalc( -a r1+orig -b r2+orig -expr 0.5*(a+b) )’ {calculation}
The default output format is to store the results as scaled short (16-bit) integers. This truncantion might cause significant errors. If you receive warnings that look like this:
+ WARNING: TvsF[0] scale to shorts misfit = 8.09% – ** Beware
then you can force the results to be saved in float format by defining the environment variable AFNI_FLOATIZE to be YES before running the program. For convenience, you can do this on the command line, as in
3dANOVA -DAFNI_FLOATIZE=YES ... other options ...
++ Compile date = Dec 16 2015