Mean Absolute Error (MAE) and Root mean squared error (RMSE) are two of the most common metrics used to measure accuracy for continuous variables. Not sure if I’m imagining it but I think there used…
L. Akoglu, D. Chau, U. Kang, D. Koutra, and C. Faloutsos. Proceedings of the 2012 ACM SIGMOD International Conference on Management of Data, page 717--720. New York, NY, USA, ACM, (2012)
D. Holten, and J. van Wijk. Proceedings of the 11th Eurographics / IEEE - VGTC conference on Visualization, page 983--998. Aire-la-Ville, Switzerland, Switzerland, Eurographics Association, (2009)
A. Telea, and O. Ersoy. Proceedings of the 12th Eurographics / IEEE - VGTC conference on Visualization, page 843--852. Aire-la-Ville, Switzerland, Switzerland, Eurographics Association, (2010)