How to replace column names based on partial string match in R?

December 24, 2023

I have a integer variable period that I use to make dummy columns as follows:

library(fastDummies)

df <- data.frame(period = c(-3, -2, -1, 0, 1, 2, 3))

df <- dummy_cols(df, select_columns = "period")

 period period_-1 period_-2 period_-3 period_0 period_1 period_2 period_3
     -3         0         0         1        0        0        0        0
     -2         0         1         0        0        0        0        0
     -1         1         0         0        0        0        0        0
      0         0         0         0        1        0        0        0
      1         0         0         0        0        1        0        0
      2         0         0         0        0        0        1        0
      3         0         0         0        0        0        0        1

I would like to replace the names of the columns for the dummies of negative and positive values of period to "lag" and "lead" respectively. The ideal output (with period_0 manually renamed to event):

 period      lag1      lag2      lag3    event    lead1    lead2    lead3
     -3         0         0         1        0        0        0        0
     -2         0         1         0        0        0        0        0
     -1         1         0         0        0        0        0        0
      0         0         0         0        1        0        0        0
      1         0         0         0        0        1        0        0
      2         0         0         0        0        0        1        0
      3         0         0         0        0        0        0        1

Any help is appreciated, thanks!

>Solution :

Double-sub will work:

colnames(df) <- sub("period_-", "lag", colnames(df)) |>
  sub("period_", "lead", x = _)
colnames(df)[colnames(df) == "lead0"] <- "event"
df
#   period lag1 lag2 lag3 event lead1 lead2 lead3
# 1     -3    0    0    1     0     0     0     0
# 2     -2    0    1    0     0     0     0     0
# 3     -1    1    0    0     0     0     0     0
# 4      0    0    0    0     1     0     0     0
# 5      1    0    0    0     0     1     0     0
# 6      2    0    0    0     0     0     1     0
# 7      3    0    0    0     0     0     0     1

With dplyr:

library(dplyr)
df %>%
  rename_with(.fn = ~
    if_else(.x == "period_0", "event",
            sub("period_", "lead", sub("period_-", "lag", .x))))
#   period lag1 lag2 lag3 event lead1 lead2 lead3
# 1     -3    0    0    1     0     0     0     0
# 2     -2    0    1    0     0     0     0     0
# 3     -1    1    0    0     0     0     0     0
# 4      0    0    0    0     1     0     0     0
# 5      1    0    0    0     0     1     0     0
# 6      2    0    0    0     0     0     1     0
# 7      3    0    0    0     0     0     0     1

Starting data

df <- structure(list(period = -3:3, "period_-1" = c(0L, 0L, 1L, 0L, 0L, 0L, 0L), "period_-2" = c(0L, 1L, 0L, 0L, 0L, 0L, 0L), "period_-3" = c(1L, 0L, 0L, 0L, 0L, 0L, 0L), period_0 = c(0L, 0L, 0L, 1L, 0L, 0L, 0L), period_1 = c(0L, 0L, 0L, 0L, 1L, 0L, 0L), period_2 = c(0L, 0L, 0L, 0L, 0L, 1L, 0L), period_3 = c(0L, 0L, 0L, 0L, 0L, 0L, 1L)), class = "data.frame", row.names = c(NA, -7L))