3dUndump issue

AFNI Message Board
1

Hi,
I want to convert the z-score values I get from 3dttest++ to pvalues and then apply a FDR correction to them. My issue is that the output of the3dUndump file is empty, whereas the input is not.

Here is the code I run:

# Convert the zscores to pvalues
3dcalc -a group_cf_ci_vs_baseline_RAI+tlrc'[1]' \
       -expr '0.5*erfc(abs(a)/sqrt(2))' \
       -prefix group_cf_ci_vs_baseline_RAI_pvalues_onetail

# Adapt the format to 1D for 3dFDR
3dmaskdump -mask mask_group_MNI+tlrc \
           group_cf_ci_vs_baseline_RAI_pvalues_onetail+tlrc > pvalues.1D

3dFDR -input pvalues.1D \
      -prefix qvalues

# Go back to 3d file
3dUndump -prefix group_cf_ci_vs_baseline_RAI_qvalues_onetail \
         -mask mask_group_MNI+tlrc \
         -master group_cf_ci_vs_baseline_RAI_pvalues_onetail+tlrc \
         -ijk qvalues.1D

Thanks a lot in advance
Laura

2

What does your qvalues.1D file look like? Does it have 4 columns of data - i j k val?