The Pie Chart viewlet presents a typical pie chart that the user can set up with a variety of comparable values. This is a type of presentation graphic in which percentage values are represented as proportionally-sized slices of a pie. The Pie Chart is useful for making quick comparisons, and discovering the percentage of each variable compared to the whole. A typical example would be to view sub-metered loads within a building, i.e. lighting, HVAC, and plug energy loads.