Create new categorical variable

categorical

# Method 1: case_when()
umaru = umaru %>% mutate(depression = case_when(BECK < 10 ~ 1,
                                                BECK < 19 ~ 2,
                                                BECK < 30 ~ 3,
                                                BECK >= 30 ~ 4))
Method 2: Avec case_when() + between() (lisible)
library(dplyr)
umaru <- umaru %>%
  mutate(
    depression = case_when(
      dplyr::between(BECK, 0, 9)     ~ "Pas/minimale",
      dplyr::between(BECK, 10, 18)   ~ "Légère",
      dplyr::between(BECK, 19, 29)   ~ "Modérée",
      BECK >= 30                     ~ "Sévère",
      TRUE                           ~ NA_character_
    ),
    depression = factor(depression,
                        levels = c("Pas/minimale", "Légère", "Modérée", "Sévère"),
                        ordered = TRUE)
  )
)
# Method 3: cut()
library(dplyr)
umaru <- umaru %>%
  mutate(
    depression = cut(
      BECK,
      breaks = c(-Inf, 9, 18, 29, Inf),   # 0–9 ; 10–18 ; 19–29 ; 30+
      labels = c("Pas/minimale", "Légère", "Modérée", "Sévère"),
      right = TRUE,                       # intervalles (a, b] → 9 dans 1ère cat., 10 dans 2e, etc.
      include.lowest = TRUE
    )
  )
  
# Methode 4: Base R uniquement
umaru$depression <- cut(
  umaru$BECK,
  breaks = c(-Inf, 9, 18, 29, Inf),
  labels = c("Pas/minimale", "Légère", "Modérée", "Sévère"),
  right = TRUE, include.lowest = TRUE
)