Dear all, I use R 3.1.1 for Windows.
I would like to use three-dimensional scatterplots to evaluate the agreement among 3 laboratory methods in a set of 30 subjects (all subjects was evaluated with each of the three methods), using a line of best fit (slope and intercept) and the line of identity. Moreover, I would like to evaluate the SD of the residual errors (distance from line of best fit) to assess the disagreement between any method and the average value among all 3 methods. For this purpose, no single method was used as a standard to which the other 2 methods would be compared. The file is: Id method1 method2 meth3 1 5 6 6 2 4 7 6 3 8 9 12 .. ... ... ... 29 8 7 10 30 12 14 13 I know that the package "scatterplot3d" is useful for plotting the data, and also I read the previous post http://r.789695.n4.nabble.com/Fit-a-3-Dimensional-Line-to-Data-Points-td8635 96.html . However the R square and SD of the residual errors are not reported in this example. Any suggestion is welcome. ------------------------------------------------------- Mario Petretta Associate Professor of Internal Medicine Department of Translational Medical Sciences Naples University Federico II Italy ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
