Spatial data & visualization

class: center, middle, inverse, title-slide

# Spatial data & visualization

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## 1854 London Cholera Outbreak

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## Napoleon's 1812 Russia Campaign

**Many others!**

- [World Population Density](https://luminocity3d.org/WorldPopDen/#3/12.00/10.00)
- [Global Power](https://www.gocompare.com/gas-and-electricity/what-powers-the-world/)

---

## Raster versus vector spatial data

.vocab[Vector] spatial data describes the world using shapes (points, lines, 
polygons, etc).

.vocab[Raster] spatial data describes the world using cells of constant size.

The choice to use vector or raster data depends on the problem context. We will 
focus on vector data.

*Source:* https://commons.wikimedia.org/wiki/File:Raster_vector_tikz.png

---

Click the link below to create the repository for lecture notes #06
  -https://classroom.github.com/a/SwGmBhHJ
  
Follow the steps to clone the repo, make a new RStudio project, and configure
git. Change the author name in the YAML header of `lecture06.Rmd` to your name
and update the date to today's date.

<br>

Complete the Lab Team Formation Survey by 2-09 11:59 PM. Do this now if you 
have time.
 - [https://forms.gle/mZMZ53Zfy3yPHwdJ6](https://forms.gle/mZMZ53Zfy3yPHwdJ6)

---

Simple features have a geometry type. Common choices are below.

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## Spatial data plotting needs care

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## Map Layers

The North Carolina Department of Environment and Natural Resources, 
Wildlife Resources Commission and the NC Center for Geographic Information and 
Analysis has a [shapefile data set](https://www.nconemap.gov/datasets/e5ddff9b96204c6181be7c022e61d946_0) 
available on all public Game Lands in NC.

```r
nc_game <- st_read("data/gamelands.shp", quiet = TRUE)
```

---

```r
ggplot(nc_game) +
  geom_sf() +
  theme_bw() +
  labs(title = "North Carolina gamelands")
```

---

```r
ggplot(nc_game) +
  geom_sf(fill = "#ff6700") +
  theme_bw() +
  labs(title = "North Carolina gamelands")
```

---

```r
ggplot(nc) +
  geom_sf() +
  geom_sf(data = nc_game, fill = "#ff6700", alpha = .5) +
  theme_bw() +
  labs(title = "North Carolina gamelands and counties")
```

---

.tiny[

```r
ggplot(nc) +
  geom_sf() +
  geom_sf(data = nc_game, aes(alpha = SUM_ACRES), fill = "#ff6700") +
  theme_bw() +
  labs(title = "North Carolina gamelands and counties", fill = "Acres")
```

<img src="06-spatial_files/figure-html/unnamed-chunk-12-1.png" style="display: block; margin: auto;" />
]