Hello all,
I see unexpected behavior when I use 'fslcc'. I get no output when I use the '--noabs' switch.
I want to see if two eigenvariate time courses I extracted via 'fslmeants' are flipped with respect to one another. I extract the time courses:
fslmeants -i filtered_func \
-m hippoLeft -o tc_eig_hippoLeft.txt --eig
fslmeants -i filtered_func \
-m hippoRight -o tc_eig_hippoRight.txt --eig
I convert these ascii files to .nii:
nn=`fslnvols filtered_func `
fslascii2img tc_eig_hippoLeft.txt \
$nn 1 1 1 1 1 1 1 vol_eig_tc_eig_hippoLeft
fslascii2img tc_eig_hippoRight.txt \
$nn 1 1 1 1 1 1 1 vol_mean_tc_eig_hippoRight
Then compute the cross correlation without and with the --noabs switch:
# without --abs switch
fslcc -t 0 -p 6 vol_eig_tc_eig_hippoLeft vol_mean_tc_eig_hippoRight
1 1 0.838791
# with --abs switch
fslcc --noabs -t 0 -p 6 vol_eig_tc_eig_hippoLeft vol_mean_tc_eig_hippoRight
When I plot these two eigenvariates, I can see they are anti-correlated. In the above example, when using the --noabs switch I expected a negative value, -0.838791. Instead, I get no output.
Just in case, I also tried --noabs=1 and --noabs=0 and got no output. I also moved the position of the --noabs switch within the command -- still no output. Any suggestions?
I am trying to avoid popping into matlab.
Thanks,
* ba
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