HDS 2.3-2.4

Author

Andrew Weiser

library(palmerpenguins)
library(tidyverse)

Begin by loading the tidyverse and palmerpenguins packages above.

Take a glimpse of the penguins data and determine which of the variables are categorical and which are quantitative:

glimpse(penguins)

Rows: 344
Columns: 8
$ species           <fct> Adelie, Adelie, Adelie, Adelie, Adelie, Adelie, Adel…
$ island            <fct> Torgersen, Torgersen, Torgersen, Torgersen, Torgerse…
$ bill_length_mm    <dbl> 39.1, 39.5, 40.3, NA, 36.7, 39.3, 38.9, 39.2, 34.1, …
$ bill_depth_mm     <dbl> 18.7, 17.4, 18.0, NA, 19.3, 20.6, 17.8, 19.6, 18.1, …
$ flipper_length_mm <int> 181, 186, 195, NA, 193, 190, 181, 195, 193, 190, 186…
$ body_mass_g       <int> 3750, 3800, 3250, NA, 3450, 3650, 3625, 4675, 3475, …
$ sex               <fct> male, female, female, NA, female, male, female, male…
$ year              <int> 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2007…

Make a list of the categorical variables:

species
island
sex
year

Make a list of the quantitative variables:

bill length
bill depth
flipper
body

Summarizing Variables

Create a code chunk that summarizes the number of penguins by species:

count(penguins, species)

# A tibble: 3 × 2
  species       n
  <fct>     <int>
1 Adelie      152
2 Chinstrap    68
3 Gentoo      124

Create a code chunk that summarizes the number of penguins by island:

count(penguins, island)

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

Create a code chunck that summarizes the number of penguins by species and island:

count(penguins, species, island)

# A tibble: 5 × 3
  species   island        n
  <fct>     <fct>     <int>
1 Adelie    Biscoe       44
2 Adelie    Dream        56
3 Adelie    Torgersen    52
4 Chinstrap Dream        68
5 Gentoo    Biscoe      124

Create a code chunk that summarizes body_mass_g. It should produce a data frame with the mean, median, minimum, maximum, and standard deviation of the body_mass_q:

summarize(
  penguins,
  Mean_Mass   = mean(body_mass_g, na.rm = TRUE),
  Median_Mass = median(body_mass_g, na.rm = TRUE),
  Min_Mass    = min(body_mass_g, na.rm = TRUE),
  Max_Mass    = max(body_mass_g, na.rm = TRUE),
  SD_Mass     = sd(body_mass_g, na.rm = TRUE)
)

# A tibble: 1 × 5
  Mean_Mass Median_Mass Min_Mass Max_Mass SD_Mass
      <dbl>       <dbl>    <int>    <int>   <dbl>
1     4202.        4050     2700     6300    802.