Easier way to add another column if values in another fall within a range in R

Question

[unawaaz]

Hi everyone,

I have a dataset and I want to add another column where I want to label based on the range.

My df is essentially Ages and I want to have another column that is Age Interval. My code works when my ages are over 0 but not sure how to do this when I have negative values (pcw). To achieve what I want, this is what I'm currently doing:

df$AgeInterval[df$Age >= -0.701 & df$Age <= -0.62] = "4-7pcw"
df$AgeInterval[df$Age >= -0.621 & df$Age <= -0.58] = "8-9pcw"
df$AgeInterval[df$Age >= -0.57 & df$Age <= -0.53] = "10-12pcw"

But there has to be a simpler way to do this?

Normally to do this I would use this for values over 0 and it gets the job done:

df %<>% mutate(age_interval = as.character(cut(Age, seq(-1, 100, by = 10)))) %>% 
  mutate(AgeInterval = sapply(age_interval, function(i) {
    paste0(
      as.numeric(gsub("^\\(([-0-9]+),.+", "\\1", i)) + 1,
      "-",
      as.numeric(gsub(".+,([0-9]+)\\]$", "\\1", i)), "yrs"
    )})) %>% 
  dplyr::select(-age_interval)

[Basti]

How many categories do you have ?

[unawaaz]

13 in total

[Trivas]

You could use case_when and between within mutate. ie:

df %>% mutate(AgeInterval = case_when(between(age, -0.701, -0.62) ~ "4-7pcw",
                                      between(age, -0.621, -0.58) ~ "8-9pcw")

[LauferVA]

strongly consider reading the docs or working thru the vignettes for for data.table

Answer 1

[zx8754]

Read about cut and try this example:

set.seed(1); x <- runif(100, -1, 1)

xCut <- cut(x, breaks = seq(-1, 1, 0.5), labels = paste0("age", 1:4))

head(xCut)
# [1] age2 age2 age3 age4 age1 age4
# Levels: age1 age2 age3 age4

table(xCut)
# xCut
# age1 age2 age3 age4 
#   20   32   21   27 

[unawaaz]

What do I do if the break is not 0.5?

[zx8754]

You can put any breaks you need, for example, this will give you 2 groups -1 to 0 and 0 to 1: breaks = c(-1, 0, 1)