TidyRtesting.Rmd

---
title: "TidyRtesting"
author: "John Ryan"
date: "12/1/2017"
output: html_document
---

```{r}
library(tidyverse)
library(tidyr)
```

## Example datsets

## command option i to insert new R block
```{r}
AirPassengers
```

```{r}
## wide format
gap_wide <- readr::read_csv('https://raw.githubusercontent.com/OHI-Science/data-science-training/master/data/gapminder_wide.csv')


## yesterdays data format
gapminder <- readr::read_csv('https://raw.githubusercontent.com/OHI-Science/data-science-training/master/data/gapminder.csv')

head(gap_wide)

## Use gather to turn `gap_wide` into long format dataset
gap_long <- gap_wide %>%
  gather(key = obstype_year,
         value = obs_values,
         dplyr::starts_with('pop'),
         dplyr::starts_with("lifeExp"),
         dplyr::starts_with("gdpPercap"))
```

## separate out the year
```{r}
gap_long <- gap_wide %>%
  gather(key = obstype_year,
         value = obs_values,
         -continent, - country) %>%
  separate(obstype_year,
           into = c("obs_type", "year"),
           sep = "_",
           convert = T)

head(gap_long)

```

## plot long format data
```{r}
life_df <- gap_long %>%
  filter(obs_type == "lifeExp",
         continent == "Americas")
head(life_df)

ggplot(data = life_df, aes(x = year, y = obs_values, color = country)) +
  geom_line()
```

## exercise: using gap_long mean life expectancy for each continent 1982 - 2007
## hint: use the dplyr::group_by() and dplyr::summarize() functions.
```{r}
# solution (no peeking!)
gap_long %>% 
  group_by(continent, obs_type) %>%
    summarize(means = mean(obs_values))

cont <- gap_long %>% 
  filter(obs_type == "lifeExp", 
         year > 1980) %>% 
  group_by(continent, year) %>% 
  summarize(mean_le = mean(obs_values))

ggplot(data = cont, aes(x = year, y = mean_le, color = continent)) + 
  geom_line() +
  labs(title = "Mean life expectancy",
       x = "Year",
       y = "Age (years)") 

## Additional customization
ggplot(data = cont, aes(x = year, y = mean_le, color = continent)) + 
  geom_line() +
  labs(title = "Mean life expectancy",
       x = "Year",
       y = "Age (years)",
       color = "Continent") +
  theme_classic() +
  scale_fill_brewer(palette = "Blues") 
```