---

title: "Custom and Animated Maps"

author: "Angela Li"

date: "2/19/2019"

output: html_document

---

```{r setup, include=FALSE}

knitr::opts_chunk$set(echo = TRUE)

```

> Tip: Use the `Ctrl-Opt-I` keyboard shortcut to insert a code chunk into your Markdown document.

## Load packages

```{r warning=FALSE, message=FALSE}

library(sf)

library(ggplot2)

library(spData)

library(tmap)

library(magick)

```

## Look at data

```{r}

head(urban_agglomerations)

str(urban_agglomerations)

names(urban_agglomerations)

```

```{r}

tail(urban_agglomerations)

```

Looks like `urban_agglomerations` is a panel-data version of population of global cities, between 1950 and 2030.

## Make a ggplot2 map

```{r}

ggplot(urban_agglomerations) +

geom_sf()

```

```{r echo=FALSE, warning=FALSE, message=FALSE, results='hide'}

# I had to do this because my spData for some reason was weird, you may not need to do this

library(dplyr)

names(world)

world <- rename(world, geometry = geom)

names(world)

```

```{r}

ggplot(world) +

geom_sf()

```

```{r}

ggplot() +

geom_sf(data = world) +

geom_sf(data = urban_agglomerations)

```

## Move it over to tmap!

### Single custom map

```{r}

tm_shape(world) +

tm_polygons() +

tm_shape(urban_agglomerations) +

tm_dots(size = "population_millions", title.size = "Population (m)", col = "red")

```

### Map with small multiples

```{r}

tm_shape(world) +

tm_polygons() +

tm_shape(urban_agglomerations) +

tm_dots(size = "population_millions", title.size = "Population (m)", col = "red") +

tm_facets(by = "year")

```

### Map (animated!!)

```{r}

tm <- tm_shape(world) +

tm_polygons() +

tm_shape(urban_agglomerations) +

tm_dots(size = "population_millions", title.size = "Population (m)", col = "red") +

tm_facets(along = "year", free.coords = FALSE)

tmap_animation(tm, "city-pop-anim.gif", loop = TRUE, delay = 80)

```

```{r}

magick::image_read("city-pop-anim.gif")

```