Dear list, I have two things I am struggling...
# First set.seed(123) myD <- data.frame( Light = sample(LETTERS[1:2], 10, replace=T), Feed = sample(letters[1:5], 20, replace=T), value=rnorm(20) ) # Mean for Light myD$meanLight <- unlist( lapply( myD$Light, function(x) mean( myD$value[myD$Light == x]) ) ) # Mean for Feed myD$meanFeed <- unlist( lapply( myD$Feed, function(x) mean( myD$value[myD$Feed == x]) ) ) myD # I would like to get a new Var "meanLightFeed" # holding the "Group-Mean" for each combination (eg. A:a = 0.821581) # by(myD$value, list(myD$Light, myD$Feed), mean)[[1]] # Second set.seed(321) myD <- data.frame( Light = sample(LETTERS[1:2], 10, replace=T), value=rnorm(20) ) w1 <- tapply(myD$value, myD$Light, mean) w1 # > w1 # A B # 0.4753412 -0.2108387 myfun <- function(x) (myD$value > w1[x] & myD$value < w1[x] * 1.5) I would like to have a TRUE/FALSE-Variable depend on the constraint in "myfun" for each level in "Light"... As always - thanks for any help!! Patrick ______________________________________________ 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.