Comparison of % variance explained by each PC before AND after rotation
Hello again- Thanks to Prof. Ripley for responding to my previous question. I would like to clarify my question using sample code. I will use some sample code taken from ?prcomp Again, I would like to compare the % variance explained by each PC before and after rotation. < code follows > data(USArrests) pca = prcomp(USArrests, scale = TRUE) # proportion variance explained by each PC prop = pca$sdev^2/sum(pca$sdev^2) # cumulative proportion variance explained by each PC cumProp = cumsum(prop) # following print statements also can be obtained # from print(summary(pca)) #print(prop) #print(cumProp) print(summary(pca)) # Rotate the PCA loadings through PCs 1 and 2 using VARIMAX rotation rot = varimax(pca$rotation[,1:2], normalize = TRUE, eps = 1e-5) < end code > How can I calculate the new % variance explained by each PC after rotation ?????? Many thanks once more,
Maurice J. McHugh, Ph.D. Assistant Professor Department of Geography and Anthropology 227 Howe Russell Geoscience Complex Louisiana State University Phone: (225)578-0476 Baton Rouge, LA Fax: (225)578-4420 USA