afni.nimh.nih.gov

Dear Rick

Hi
Thank you so much for your reply.
Sorry for this dumb question of mine.
How can I learn more about every sub command in afni?
i.e about:
3dcalc -a anat.float+orig -expr a -datum short -prefix anat.short
As much as I know "3dcalc" is the command part.However,I have no idea about
"-a" , "anat.float+orig" , "-expr" and the rest.Where should I substitute inorder to include my data name as an input?

Best,
Mahsa