summarize dplyr code example

Example 1: dplyr group by intervals of 3

d %>% mutate( ints = cut(v1 ,breaks = 11)) %>% 
   group_by(ints) %>% 
   summarise( mean.v2 = mean(v2) , mean.v3 = mean(v3) )

Example 2: dplyr average columns

library(dplyr)
mutate(df, IVMean = rowMeans(select(., starts_with("IV")), na.rm = TRUE))