search for: testfactor

Dear list, Please find below an example of odd behaviour of the by function. It occurs both under GNU/Linux R 2.6.2 and Windows R 2.7.0alpha. Respective sessionInfo()'s are given below. I hope I do not overlook anything. testFactor <- factor(sample(LETTERS[1:6], size = 42, replace = TRUE)) testMatrix <- matrix(rnorm(42 * 6), nrow = 42) testDf <- as.data.frame(testMatrix) by(data = testDf, INDICES = testFactor, FUN = mean) # OK by(data = testDf, INDICES = testFactor, FUN = median) # error # Error in median.default(da...

...hia" (Post-Hoc Interaction Analysis) is aimed at the analysis of the expected values and other terms of in linear, generalized, and mixed linear models, on the basis of multiple comparisons of factor contrasts, and is specially suited for the analysis of interaction effects. The function "testFactors" provides a flexible user interface for defining combinations of factor levels and covariates, to evaluate and test the model, using the function "linearHypothesis" from package "car". "testInteractions" gives a simpler interface to test multiple comparisons of s...

...hia" (Post-Hoc Interaction Analysis) is aimed at the analysis of the expected values and other terms of in linear, generalized, and mixed linear models, on the basis of multiple comparisons of factor contrasts, and is specially suited for the analysis of interaction effects. The function "testFactors" provides a flexible user interface for defining combinations of factor levels and covariates, to evaluate and test the model, using the function "linearHypothesis" from package "car". "testInteractions" gives a simpler interface to test multiple comparisons of s...