---
title: "Data exploration using the palmerpenguins dataset"
author: "Olivier Gimenez"
date: "10/25/2020"
output:
  word_document: default
  pdf_document: default
  html_document: default
bibliography: mabiblio.bib
---

```{r setup, include = FALSE}
knitr::opts_chunk$set(echo = TRUE, message = FALSE)
```

# 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 @Connors2020.

```{r echo = FALSE}
library(palmerpenguins)
library(tidyverse)
```

## Data

The data are displayed below (first 10 rows) : 
```{r}
penguins %>% 
  slice(1:10) %>%
  knitr::kable()
```

## Numerical exploration

There are `r nrow(penguins)` penguins in the dataset, and `r length(unique(penguins$species))` different species. The data were collected in `r length(unique(penguins$island))` islands of the Palmer archipelago in Antarctica. 

The mean of all traits that were measured on the penguins are:
```{r echo = FALSE}
penguins %>% 
  group_by(species) %>% 
  summarize(across(where(is.numeric), mean, na.rm = TRUE))
```


## Graphical exploration

A histogram of body mass per species:
```{r}
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")
```


## The end

The 3 species of penguins: 

![](lter_penguins.png)



## References
