Hi everyone,
I have analyses that were done in 3dMVM, which give me f statistics. I am trying to write a script that thresholds these maps using a p-value and a minimum cluster size, using the 3dclusterize command. I was always under the impression that I should use a 2-sided test for these f-values, because the underlying contrast could be bi-directional (i.e. exp > control or control > exp). Is this standard practice?
2-tailed seems to be the default in the afni GUI (e.g. F(1,27) = 13.61; p = 001). However, if I try to replicate this behavior in 3dclusterize by using a 2-sided test, I get the following error:
** FATAL ERROR: You are asking for multisided clustering on a single-sided stat!
Other than using a 1-sided test with p=p/2, is there a way to override this error?
Thanks,
-nick
