fix the indeterminant system in stereo case

matlab/+gtsam/cylinderSampleProjectionStereo.m

@@ -42,6 +42,11 @@ for i = 1:cylinderNum
             continue;       
         end            
 
+        % too small disparity may call indeterminant system exception
+        if Z.du < 0.6
+            continue;
+        end
+        
         % ignore points occluded
         % use a simple math hack to check occlusion:
         %   1. All points in front of cylinders' surfaces are visible