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variable: $normdsampuniqvtxflag -- toggle uniq
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default: 0

"NormSamp, Clust Controls" parameter.  To adjust,
access pop-up by L-click on "label:" (bold).

This flag only affects the operation of:

  write_label_timecourses_stats
  ("label:" line "T" and "S" buttons)

It has no effect on:

  paint_surface
  ("val3d:" line "PAINT" button)

If ticked, timecourses (and/or stats) are only
written out once for each uniq voxel sampled by
the vertices in the input label, as when
$normdsampuniqvoxflag is set.

But in addition, the vertex that 'owns' the voxel
is the one closest to the average location of all
of the vertices that sampled the voxel (as
opposed to the first vertex to sample the voxel).

This requires doing the three operations on the
"val3d:" line (if not visible, click "val:" to
toggle to it):

 (1) one 3D native stats file is loaded with R
 (2) it is sampled to the surface with PAINT
 (3) UQ is run to find uniqsamp vertices
