我有以下数据框:
df <- data.frame(a = c(1:20),
b = c(2:21),
c = as.factor(c(rep(1,5), rep(2,10), rep(3,5))))
我想做以下事情:
df1 <- df %>% group_by(c) %>% mutate(a = lead(b))
但最初我有许多变量,我需要将lead()
函数与group_by()
多个变量结合应用。我正在努力purrr::pmap()
实现这一目标:
df2 <- pmap(list(df[,1],df[,2],df[,3]), function(x,y,z) group_by(z) %>% lead(y))
不幸的是,这会导致错误:
Error in UseMethod("group_by_") :
no applicable method for 'group_by_' applied to an object of class "c('integer', 'numeric')"