Reshaping data frame with old variables to be new rownames tidyverse

how are you?

I am struggling trying to reshape a data frame in R. Im working on a Shiny App and i need to reshape my data on a way that in the columns i have the values for two different years, so i can calculate the variation. The main idea is that the user can select two different years and view the variation for different KPI’s.

Suppose this is my data:

df <- data.frame(
  PERIOD = c(2020, 2021),
  map = c(1, 2),
  mac = c(1, 4)
)

I would like the new data frame to have two columns (year 2020, year 2021) and "map" "mac" to be the values of a new variable called "kpi".

Hope you can help me,

already thank you!!

>Solution :

library(tidyr)

pivot_longer(df, cols = -PERIOD, names_to = "kpi") |>
  pivot_wider(names_from = PERIOD, names_prefix = "year")

Output

  kpi   year2020 year2021
1 map          1        2
2 mac          1        4