Dear experts,
I have run randomise using the TFCE option (-T), producing t-statistic maps. I am using FSL Version 5.0.9. I have subsequently run “cluster" on the randomise output in order to extract significant clusters, but I would like to retrieve the p-value of the clusters using the GRF option.
I know that I need to supply --dlh (smoothness estimate), --volume (number of voxels in mask) and --pthresh (p-value threshold for clusters), where I use the “smoothest" function to determine values for --dlh and --volume.
The “cluster” command I run is:
cluster --in=output_tfce_thresh_tstat2.nii.gz --dlh=0.0239923 --volume=611340 --pthresh=0.95 -t 0.95 --oindex=output_cluster_index.nii.gz --olmax=output_lmax.txt --osize=output_cluster_size.nii.gz
Unfortunately, I get “nan” returned for the cluster p-vlaue:
Cluster Index Voxels P -log10(P) MAX MAX X (vox) MAX Y (vox) MAX Z (vox) COG X (vox) COG Y (vox) COG Z (vox)
1 1786 nan -nan 17.7 43 86 43 43.2 84 48.2
whereas when I run without any GRF options, I see the following:
Cluster Index Voxels MAX MAX X (vox) MAX Y (vox) MAX Z (vox) COG X (vox) COG Y (vox) COG Z (vox)
1 1786 17.7 43 86 43 43.2 84 48.2
I am unsure why I am getting nan values when using GRF options. Any help would be much appreciated!
Cheers,
Donal
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