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In some cases, however, the cluster approach is performing better than the manual approach. This appears to negate the fact that the manual approach chooses the circle with the minimum error distance. So how can this be? then can the how this could be minimum then 'minimum error distance circle' its because landmarks keep on changing due to which clusters keep on changing so minimum error distance circles keep on changing.
A comparison of the accuracies yielded by the two methods is seen below: 
It is seen that there is little difference with the manual method in general being slightly better.
Cluster Method
Manual Method
Comparison Graph of both techniques
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