Hi Rick,
The same thing happened to me too (see below) in which 3dclust found something whereas 3dmerge didn't:
3dmerge -prefix *** -1thresh 5.01 -1clust 2 -402 anova+tlrc[12,13]
Program 3dmerge
++ 3dmerge: AFNI version=AFNI_2008_02_01_1144 (Apr 14 2008) [32-bit]
3dmerge: edit and combine 3D datasets, by RW Cox
++ default -1dindex = 0
++ default -1tindex = 1
++ editing input dataset in memory (3.4 MB)
*** NO CLUSTERS FOUND ***
3dclust -1tindex anova+tlrc[13] -1thresh 5.01 2 402 anova+tlrc[12]
++ 3dclust: AFNI version=AFNI_2008_02_01_1144 (Apr 14 2008) [32-bit]
++ Authored by: RW Cox et al
#
#Cluster report for file anova+tlrc[12]
#[Connectivity radius = 2.00 mm Volume threshold = 408.00 ]
#[Single voxel volume = 8.0 (microliters) ]
#[Voxel datum type = short ]
#[Voxel dimensions = 2.000 mm X 2.000 mm X 2.000 mm ]
#[Coordinates Order = RAI ]
#Mean and SEM based on Absolute Value of voxel intensities:
#
#Volume CM RL CM AP CM IS minRL maxRL minAP maxAP minIS maxIS Mean SEM Max Int MI RL MI AP MI IS
#------ ----- ----- ----- ----- ----- ----- ----- ----- ----- ------- ------- ------- ----- ----- -----
1288 -37.5 -65.4 -42.4 -44.0 -32.0 -72.0 -56.0 -48.0 -36.0 5.5668 0.0303 6.4091 -36.0 -68.0 -44.0
