floor and ceil seems wrong here (see documentation astra_create_vol_geom)

functions/tomography/astraWrappers/astraFDK.m

@@ -156,8 +156,8 @@ end
 % coordinate in y, minimum coordinate in z, maximum coordinate in z
 volGeom = astra_create_vol_geom(settings.outputSize, settings.outputSize, ...
     settings.numSlices, -settings.outputSize/2, settings.outputSize/2, ...
-    -settings.outputSize/2, settings.outputSize/2, settings.offset - floor(settings.numSlices/2), ...
-    settings.offset + ceil(settings.numSlices/2));
+    -settings.outputSize/2, settings.outputSize/2, settings.offset - settings.numSlices/2, ...
+    settings.offset + settings.numSlices/2);
 % create initial volume for the reconstruction
 volID = astra_mex_data3d('create', '-vol', volGeom);