how to apply functions on data frame in r

Question

How can i apply the following function rt on each and every value l in df. x and y have the following values.

 x<-9
 y<-1

rt<-function(x,y,l) min(x,max(0,l-y))

df
a   b   c
5   6   7
1   4   1
2   4   3

`rt(x, y, unlist(df))`? And are you sure you actually want `df` as a `data.frame` and not a `matrix`? — MichaelChirico, Mar 23 '16 at 14:03
http://stackoverflow.com/questions/5158790/data-frame-or-matrix — MichaelChirico, Mar 23 '16 at 14:07

score 2 · Accepted Answer · edited Mar 23 '16 at 14:22

Probably simplest if you'd like to stick with dataframes is to use apply with the MARGIN parameter set to c(1,2), which makes it apply the function by both rows and columns (i.e., to every cell).

x <- 9
y <- 1

rt <- function(x, y, l) min(x, max(0, l-y))

df <- data.frame(a = c(5, 1, 2),
                 b = c(6, 4, 4),
                 c = c(7, 1, 3))

rt_df <- as.data.frame(apply(df, c(1,2), rt, x = x, y = y))

how to apply functions on data frame in r

1 Answers1