Mario Petretta
2014-Oct-31 15:31 UTC
[R] 3D scatterplot and agreement among three methods in the same subject
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
Dear all, I use R 3.1.1 for Windows. I performed two different meta-analysis assessing the prognostic value of two different tests in patients with coronary artery disease. The study included in the two analysis are different. The variable of interest in dichotomous (normal/abnormal result) for both tests. The effects size is hazard ratio and its standard error (ln units) for both meta-analysis. I would like to statistically compare the two summary hazard ratios and 95% CI (eform) obtained from the two meta-analysis. For one meta-analysis: HR 3.12 (95% CI 2.2 - 4.1) For the other: HR 1.25 (95% CI 1.03 - 2.6) It is possible or I'm comparing apples with oranges? Any suggestion is welcome. ------------------------------------------------------- Mario Petretta Associate Professor of Internal Medicine Department of Translational Medical Sciences Naples University Federico II Italy --- Questa e-mail ? stata controllata per individuare virus con Avast antivirus. http://www.avast.com