AFNI program: 3dANOVA3

Output of -help


This program performs three-factor ANOVA on 3D data sets.           

Usage: 
3dANOVA3 
-type  k          type of ANOVA model to be used:
                         k = 1   A,B,C fixed;          AxBxC
                         k = 2   A,B,C random;         AxBxC
                         k = 3   A fixed; B,C random;  AxBxC
                         k = 4   A,B fixed; C random;  AxBxC
                         k = 5   A,B fixed; C random;  AxB,BxC,C(A)

-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
-dset 1 1 1 filename           data set for level 1 of factor A
                                        and level 1 of factor B
                                        and level 1 of factor C
 . . .                           . . .

-dset i j k filename           data set for level i of factor A
                                        and level j of factor B
                                        and level k of factor C
 . . .                           . . .

-dset a b c filename           data set for level a of factor A
                                        and level b of factor B
                                        and level c of factor C

[-voxel num]                   screen output for voxel # num
[-diskspace]                   print out disk space required for
                                  program execution


The following commands generate individual AFNI 2 sub-brick datasets:
  (In each case, output is written to the file with the specified
   prefix file name.)

[-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
[-xmean i j k prefix]       estimate mean of cell at factor A level i,
                               factor B level j, factor C level k

[-adiff i j prefix]         difference between factor A levels i and j
                               (with factors B and C collapsed)
[-bdiff i j prefix]         difference between factor B levels i and j
                               (with factors A and C collapsed)
[-cdiff i j prefix]         difference between factor C levels i and j
                               (with factors A and B collapsed)
[-xdiff i j k l m n prefix] difference between cell mean at A=i,B=j,
                               C=k, and cell mean at A=l,B=m,C=n

[-acontr c1...ca prefix]    contrast in factor A levels
                               (with factors B and C collapsed)
[-bcontr c1...cb prefix]    contrast in factor B levels
                               (with factors A and C collapsed)
[-ccontr c1...cc prefix]    contrast in factor C levels
                               (with factors A and B collapsed)

[-aBcontr c1 ... ca : j prefix]   2nd order contrast in A, at fixed
                                     B level j (collapsed across C)
[-Abcontr i : c1 ... cb prefix]   2nd order contrast in B, at fixed
                                     A level i (collapsed across C)

[-aBdiff i_1 i_2 : j prefix] difference between levels i_1 and i_2 of
                               factor A, with factor B fixed at level j

[-Abdiff i : j_1 j_2 prefix] difference between levels j_1 and j_2 of
                               factor B, with factor A fixed at level i

[-abmean i j prefix]         mean effect at factor A level i and
                               factor B level j

The following command generates one AFNI 'bucket' type dataset:

[-bucket prefix]         create one AFNI 'bucket' dataset whose
                           sub-bricks are obtained by concatenating
                           the above output files; the output 'bucket'
                           is written to file with prefix file name

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

[-old_method]       request to perform ANOVA using the previous
                    functionality (requires -OK, also)

[-OK]               confirm you understand that contrasts that
                    do not sum to zero have inflated t-stats, and
                    contrasts that do sum to zero assume sphericity
                    (to be used with -old_method)

[-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).

-----------------------------------------------------------------
example: "classic" houses/faces/donuts for 4 subjects (2 genders)
         (level sets are gender (M/W), image (H/F/D), and subject)

    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


N.B.: For this program, the user must specify 1 and only 1 sub-brick
      with each -dset command. That is, if an input dataset contains
      more than 1 sub-brick, a sub-brick selector must be used, e.g.:
      -dset 2 4 5 'fred+orig[3]'

INPUT DATASET NAMES
-------------------
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}
For the gruesome details, see the output of 'afni -help'.

++ Compile date = Jul 24 2008


This page auto-generated on Fri Jul 25 01:23:46 EDT 2008