Module 11: Apply it to your data 10

Import your data

penguins <- readr::read_csv('https://raw.githubusercontent.com/rfordatascience/tidytuesday/main/data/2025/2025-04-15/penguins.csv') 

## Rows: 344 Columns: 8
## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr (3): species, island, sex
## dbl (5): bill_len, bill_dep, flipper_len, body_mass, year
## 
## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.

Chapter 15

Create a factor

penguins %>% count(year)

## # A tibble: 3 × 2
##    year     n
##   <dbl> <int>
## 1  2007   110
## 2  2008   114
## 3  2009   120

year_order <- c("2009", "2008", "2007")

data_rev <- penguins %>%
    mutate(year = year %>% factor(levels = year_order))

Modify factor order

Make two bar charts here - one before ordering another after

data_summary <- penguins %>%
  group_by(sex) %>%
  summarise(
    body_mass = mean(body_mass, na.rm = TRUE)
  )
data_summary

## # A tibble: 3 × 2
##   sex    body_mass
##   <chr>      <dbl>
## 1 female     3862.
## 2 male       4546.
## 3 <NA>       4006.

ggplot(data_summary, aes(body_mass, sex)) + geom_point()

ggplot(data_summary, aes(body_mass, fct_reorder(sex, body_mass))) + geom_point()

Modify factor levels

Show examples of three functions:

• fct_recode

penguins %>%
    mutate(sex = fct_recode(sex,
                             "female" = "ladies",
                             "male" = "men")) %>%
    count(sex)

## Warning: There was 1 warning in `mutate()`.
## ℹ In argument: `sex = fct_recode(sex, female = "ladies", male = "men")`.
## Caused by warning:
## ! Unknown levels in `f`: ladies, men

## # A tibble: 3 × 2
##   sex        n
##   <fct>  <int>
## 1 female   165
## 2 male     168
## 3 <NA>      11

• fct_collapse

penguins %>%
    mutate(island = fct_collapse(island, 
                                 main_islan = "Biscoe",
                                 other = "Dream", "Torgersen
",
)) %>%
count(island)

## Warning: There was 1 warning in `mutate()`.
## ℹ In argument: `island = fct_collapse(...)`.
## Caused by warning:
## ! Unknown levels in `f`: Torgersen

## # A tibble: 3 × 2
##   island         n
##   <fct>      <int>
## 1 main_islan   168
## 2 other        124
## 3 Torgersen     52

• fct_lump

penguins %>%
    mutate(island = fct_lump(island)) %>%
    count(island) 

## # A tibble: 3 × 2
##   island     n
##   <fct>  <int>
## 1 Biscoe   168
## 2 Dream    124
## 3 Other     52

Chapter 16

No need to do anything here.