Examples of animating data visualizations in R

animation.qmd

---
title: "Animated Data Visualizations in R"
execute:
  warning: false
  message: false
---

## Load packages

First, we load the packages that we'll use below:

```{r}
library(tidyverse)
#remotes::install_github("hrbrmstr/cdcfluview")
library(cdcfluview)
library(MMWRweek)
library(tidyverse)
library(plotly)
library(gganimate)
```

## Retrieve and prep data

The code below will pull data from ILInet and then do some minimal processing to filter for Virginia and Texas:

```{r}
## pull data from ILInet via cdcfluview package
ili <- ilinet(region = "state")

## data prep for virginia and texas
vatx <-
  ili %>%
  ## convert date from epiyear and epiweek
  mutate(date = MMWRweek2Date(year, week)) %>%
  ## filter for a date range
  filter(date >= as.Date("2016-09-01") & date <= as.Date("2019-09-01")) %>%
  ## format year week combined
  mutate(yweek = paste0(year, "-", week)) %>%
  ## restrict to just virginia and texas
  filter(region %in% c("Virginia","Texas"))
```

## Static plot

Next we can create a a static plot using some basic `ggplot2`:

```{r}
p <- 
  ## create base layer for date on x axis and ili on y
  ggplot(vatx, aes(date, unweighted_ili)) +
  ## add line with color by state and frame for the year
  geom_line(aes(frame = year, group = region, color = region)) +
  ## set to minimal theme
  theme_minimal() +
  ## put the legend on the bottom
  theme(legend.position = "bottom")

p
```

## `plotly`

The `ggplot2` object can be directly converted with `ggplotly()` and customized with animation options:

```{r}
fig <- 
  ## convert static ggplot2 plot to plotly object
  ggplotly(p) %>%
  ## set animation options
  animation_opts(frame = 2000, easing = "linear", redraw = FALSE
  ) %>%
  ## define where to place the "play" button for animation
  animation_button(
    x = 1, xanchor = "right", y = -0.75, yanchor = "bottom"
  ) %>%
  ## add text to the slider 
  animation_slider(
    currentvalue = list(prefix = "YEAR ", font = list(color="black"))
  )

fig
```

## `gganimate`

The `gganimate` package can also animate a `ggplot2` object with `transition_time()`:

```{r}
## add transition with transition_time
p +
  transition_time(year)
```

And also with `transition_reveal()`:

```{r}
## add transition with transition_reveal
p +
  transition_reveal(date)
```

animation.R

## -------------------------------------------------------------------------------------------------------------------
library(tidyverse)
#remotes::install_github("hrbrmstr/cdcfluview")
library(cdcfluview)
library(MMWRweek)
library(tidyverse)
library(plotly)
library(gganimate)


## -------------------------------------------------------------------------------------------------------------------
## pull data from ILInet via cdcfluview package
ili <- ilinet(region = "state")

## data prep for virginia and texas
vatx <-
  ili %>%
  ## convert date from epiyear and epiweek
  mutate(date = MMWRweek2Date(year, week)) %>%
  ## filter for a date range
  filter(date >= as.Date("2016-09-01") & date <= as.Date("2019-09-01")) %>%
  ## format year week combined
  mutate(yweek = paste0(year, "-", week)) %>%
  ## restrict to just virginia and texas
  filter(region %in% c("Virginia","Texas"))


## -------------------------------------------------------------------------------------------------------------------
p <- 
  ## create base layer for date on x axis and ili on y
  ggplot(vatx, aes(date, unweighted_ili)) +
  ## add line with color by state and frame for the year
  geom_line(aes(frame = year, group = region, color = region)) +
  ## set to minimal theme
  theme_minimal() +
  ## put the legend on the bottom
  theme(legend.position = "bottom")

p


## -------------------------------------------------------------------------------------------------------------------
fig <- 
  ## convert static ggplot2 plot to plotly object
  ggplotly(p) %>%
  ## set animation options
  animation_opts(frame = 2000, easing = "linear", redraw = FALSE
  ) %>%
  ## define where to place the "play" button for animation
  animation_button(
    x = 1, xanchor = "right", y = -0.75, yanchor = "bottom"
  ) %>%
  ## add text to the slider 
  animation_slider(
    currentvalue = list(prefix = "YEAR ", font = list(color="black"))
  )

fig


## -------------------------------------------------------------------------------------------------------------------
## add transition with transition_time
p +
  transition_time(year)


## -------------------------------------------------------------------------------------------------------------------
## add transition with transition_reveal
p +
  transition_reveal(date)