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

## Introduction

## Prerequsites 

```{r}
library(sf)
library(tidyverse)
library(terra)
```

```{r}
# practice filtering a raster

```

```{r}
# set all cells to NA based on condition

```

```{r}
# let's practice combining (or unioning) geometries
# read in shapefile of the counties of North Carolina

```

```{r}
# combines all geometries without resolving borders

```

```{r}
# finds the union of all geometries

```

```{r}
# let's exploring removing geometries
# pick a few counties to remove

```

```{r}
# plot counties on top of the unioned version of NC

```

```{r}
# create a new geometry that is the difference between the unioned version of NC and the counties

```

```{r}
# plot the difference on top of the unioned version of NC
# counties should be missing!

```
