# Assuming your data is in a data frame named 'df' library(dplyr) df <- data.frame( trt = c("control", "early term", "late termination", "plant green"), mean = c(231, 214, 203, 176), sd = c(12.3, 14.6, 9.40, 28.5) ) # Define character values corresponding to each treatment group character_values <- c("A", "B", "C", "D") # Adding a new column with character values df <- df %>% mutate(Character_Column = character_values) print(df)