Dear All,
I refer to the excellent post at
https://purrple.cat/blog/2018/03/02/multiple-lags-with-tidy-evaluation/
What I want to do is to create a function capable, ? la dplyr, to
generate new columns which are a lagged version of existing columns in
a data frame.
For instance, you can do this manually as
library(dplyr)
library(rlang)
d2 <- tibble(x1 =1:10, x2=10:19, x3=50:59)
d3 <- d2%>%mutate(x1lag1=lag(x1, 1), x1lag2=lag(x1,2))
but this becomes quickly tedious when you need to take several lags of
different columns.
One solution in the link above is the following
lags <- function(var, n=10){
var <- enquo(var)
indices <- seq_len(n)
map( indices, ~quo(lag(!!var, !!.x)) ) %>%
set_names(sprintf("lag_%s_%02d", quo_text(var), indices))
}
d4 <- d2 %>%
mutate( !!!lags(x1, 3), !!!lags(x2,3) )
does anybody know how this could be made more general? I mean that I
would like to take a fixed number of lags of a list of columns (x1 and
x2, for instance), just by passing the list of columns and without
repeating the commands for x1 and x2.
Any suggestion is appreciated.
Cheers
Lorenzo