rounding columns in R dataframe based on condition

column_rounding.R

library(dplyr)
df <- structure(
  list(
    column1 = c(0.001234,
                0.564324,
                1.234342,
                0.007839,
                0.837483,
                2.493993),
    column2 = c(0.123493,
                0.005643,
                1.234342,
                0.7839,
                0.008374,
                2.493993),
    column3 = c(0.001234,
                0.564324,
                1.234342,
                0.007839,
                0.837483,
                2.493993),
    column4 = c(0.001234,
                0.564324,
                1.234342,
                0.007839,
                0.837483,
                2.493993)
  ),
  row.names = c(NA, -6L),
  class = c("tbl_df",
            "tbl", "data.frame")
)

df_rounded <- mutate_at(
  df,
  .vars = vars(column1, column2, column3, column4),
  .funs = ~ case_when(
    abs(.x) >= 1 ~ round(.x, digits = 0),
    0.1 <= abs(.x) & abs(.x) < 1 ~ round(.x, digits = 1),
    abs(.x) < 0.1 ~ round(.x, digits = 2),
  )
)