Identifying where value changes in R data.frame column and generate new column

[danut_horincas]

I want new column(New) with 1 and 0 value .1 and 0 will be generates when the value changes.
Thanks.

Value	New
5	0
5	0
6	1
5	1
2	1
2	0
2	0
2	0
2	0
10	1

[nirgrahamuk]

(start_df <- start_df2 <- data.frame(
  v = c(5L, 5L, 6L, 5L, 2L, 2L, 2L, 2L, 2L, 10L),
  goal = c(0L, 0L, 1L, 1L, 1L, 0L, 0L, 0L, 0L, 1L)
))

# in base R

start_df$new <- 1L * (c(NA, start_df$v[-length(start_df$v)]) != start_df$v)
start_df$new[is.na(start_df$new)] <- 0L
start_df

# with dplyr/tidyverse
library(tidyverse)
(start_df2 <- mutate(start_df2,
                      new = 1L * (lag(v) != v)
                    ) |>
                      replace_na(list(new = 0L)))

[technocrat]

lag requires adjustment of the initial entry, because there is nothing to compare the first 5 to and that is true of this base solution as well

v <- c(5, 5, 6, 5, 2, 2, 2, 2, 2, 10)
goal <- c(0, 0, 1, 1, 1, 0, 0, 0, 0, 1)
new <- ifelse(c(0,diff(v)) == 0,0,1)
identical(goal,new)
#> [1] TRUE

^{Created on 2023-09-26 with reprex v2.0.2}

[nirgrahamuk]

theres a base::diff() ? nice ! ; I worked too hard doing it manually in base R