Acknowledgements

The content of this module are based on materials from: olivier gimenez’s materials

Data exploration

Motivation

In this section, we explore the data from package palmerpenguins. A recent publication from the researcher, Dr Kristen Gorman, who shared the data is Connors et al. (2020).

## Warning: package 'palmerpenguins' was built under R version 4.1.1
## Warning: package 'ggplot2' was built under R version 4.1.1
## Warning: package 'readr' was built under R version 4.1.1

Data

The data are displayed below (first 10 rows) :

penguins %>% 
  slice(1:10) %>%
  knitr::kable()
species island bill_length_mm bill_depth_mm flipper_length_mm body_mass_g sex year
Adelie Torgersen 39.1 18.7 181 3750 male 2007
Adelie Torgersen 39.5 17.4 186 3800 female 2007
Adelie Torgersen 40.3 18.0 195 3250 female 2007
Adelie Torgersen NA NA NA NA NA 2007
Adelie Torgersen 36.7 19.3 193 3450 female 2007
Adelie Torgersen 39.3 20.6 190 3650 male 2007
Adelie Torgersen 38.9 17.8 181 3625 female 2007
Adelie Torgersen 39.2 19.6 195 4675 male 2007
Adelie Torgersen 34.1 18.1 193 3475 NA 2007
Adelie Torgersen 42.0 20.2 190 4250 NA 2007

Numerical exploration

There are 344 penguins in the dataset, and 3 different species. The data were collected in 3 islands of the Palmer archipelago in Antarctica.

The mean of all traits that were measured on the penguins are:

## # A tibble: 3 x 6
##   species   bill_length_mm bill_depth_mm flipper_length_mm body_mass_g  year
##   <fct>              <dbl>         <dbl>             <dbl>       <dbl> <dbl>
## 1 Adelie              38.8          18.3              190.       3701. 2008.
## 2 Chinstrap           48.8          18.4              196.       3733. 2008.
## 3 Gentoo              47.5          15.0              217.       5076. 2008.

Graphical exploration

A histogram of body mass per species:

penguins %>%
  ggplot() +
  aes(x = body_mass_g) + 
  geom_histogram(aes(fill = species), 
                 alpha = 0.5, 
                 position = "identity") +
  scale_fill_manual(values = c("darkorange","purple","cyan4")) +
  theme_minimal() +
  labs(x = "Body mass (g)",
       y = "Frequency",
       title = "Penguin body mass")
## Warning: Removed 2 rows containing non-finite values (stat_bin).

The end

The 3 species of penguins:

References

Connors, Brendan, Michael J. Malick, Gregory T. Ruggerone, Pete Rand, Milo Adkison, James R. Irvine, Robert Campbell, and Kristen Gorman. 2020. “Climate and Competition Influence Sockeye Salmon Population Dynamics Across the Northeast Pacific Ocean.” Canadian Journal of Fisheries and Aquatic Sciences 77 (6): 943–49. https://doi.org/10.1139/cjfas-2019-0422.