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+====== voi.AddSphericalVOI ======
+===== Motivation =====
+In many cases, researchers already have a priori selected areas/regions which are candidates for testing specific hypothesis, which gives greater detection power (at least when, on the other hand, researchers apply customary multiple-comparison correction algorithm if they decide to perform whole-brain searches for effects that match their hypothesis!).
+Often these regions of a priori interest are given as an estimate of a central coordinate around which a spherical shape is defined with a given radius. This method allows to create ROIs that conform with that notion.
+===== Method reference ('voi.Help('AddSphericalVOI')') =====
+<file> VOI::AddSphericalVOI  - add a spherically shaped VOI to the object
+ FORMAT:       [voi = ] voi.AddSphericalVOI(c, r);
+ Input fields:
+       c           1x3 coordinate (center)
+       r           1x1 radius (must be > 0 and < 128)
+ Output fields:
+       voi         VOI with added VOI (integer coordinates only!)</file>
+===== Example =====
+To add one specific ROI to a new VOI object around, say, coordinate (-24, -4, -22) (the Talairach Atlas resolves to the left Amygdala on that coordinate) with a radius of 6mm, you can use the following code:
+<code matlab voi_addsphericalvoi_example1.m>% create VOI object
+voi = xff('new:voi');
+% add ROI
+voi.AddSphericalVOI([-24, -4, -22], 6);</code>
+To add multiple VOIs (e.g. from a table of coordinates), you could use this:
+<code matlab voi_addsphericalvoi_example2.m>% create VOI object
+voi = xff('new:voi');
+% coordinates are in a Cx3 table, ctab, and the radius is fixed at 8mm
+% alternatively, the radius could be in column 4 in a Cx4 table
+% iterate over coordinates in table
+for cc = 1:size(ctab, 1)
+    % add coordinate
+    voi.AddSphericalVOI(ctab(cc, 1:3), 8);
+    % or alternatively:
+    % voi.AddSphericalVOI(ctab(cc, 1:3), ctab(cc, 4));
+end</code>