I am a beginner, I want to use the sliding time window method to do dynamic functional connection, how to cut 4Dfmri file by time.I can't find such a function on the homepage, or I should do it in other software

[youxian]

AFNI version info (afni -ver):
Precompiled binary linux_ubuntu_16_64: May 2 2024 (Version AFNI_24.1.08 'Publius Septimius Geta')

code text  # or delete if not needed

[ptaylor]

Hi-

OK, welcome to using AFNI, and here are some some educational materials:

• AFNI Academy series
• Additional Bootcamp recordings
• Links to AFNI handouts, keyboard shortcuts and startup tips
• Page linking to all program helps
• "Classified" program guide (AFNI programs grouped thematically)
• Quick Unix tutorial

To your question, if you want to get the first ten volumes of a time series, you can run:

3dTcat -prefix DSET_OUT DSET_IN"[0..9]"

or

3dcalc -a DSET_IN"[0..9]" -expr "a" -prefix DSET_OUT

This is using AFNI subbrick notation (note the zero-based counting, and the fact that one specifies a "closed interval", meaning it includes both endpoints), described in more detail in the afni_handouts directory of the Bootcamp data, in slide 22 of afni30_vol_dset_basics.pdf:

--pt