Posted by Denise Wu on May 14, 2002 at 18:43:53:
Hello,
We thought the command 3dfim (batch mode) is equivalent to AFNI FIM (interactive mode). However, given the same input data, the results of these two approaches seemed to be based on different numbers of sample. Specifically, we used the following ideal factor matrix in AFNI FIM:
0 0 0
1 0 0
1 1 0
9 1 1
0 9 1
0 0 9
0 0 0
1 0 0
1 1 0
9 1 1
etc...
in which 9 indicates ignored TRs, while 1 indicates TRs for task and 0 indicates TRs for baseline.
And the resulted fico file was based on 100, for example, observation samples.
However, when we use the batch mode to perform the same analysis (i.e., using 3 one-column ideal factors corresponding to the 3 columns in the ideal factor matrix specified above), the result was only based on, say, 79 observation samples.
It seems that AFNI FIM takes all TRs that are not ignored in at least one column into account, whereas the 3dfim command only takes the TRs that are not ignored in all 3 columns into account. Is this correct? If so, why the difference?
Thanks for your response in advance!
Denise