gis_in_r/RGIS2_MergingSpatialData_part0_setup.Rmd at master · AIRIOpenLab/gis_in_r · GitHub

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---
title: "Merging Spatial Data"
output:
  html_document:
    toc: true
    toc_depth: 4
    theme: spacelab
    mathjax: default
    fig_width: 6
    fig_height: 6
---


```{r knitr_init, echo=FALSE, cache=FALSE, message=FALSE}
library(knitr)
library(rmdformats)
## Global options
options(max.print="75")
opts_chunk$set(echo=TRUE,
	             cache=TRUE,
               prompt=FALSE,
               tidy=TRUE,
               comment=NA,
               message=FALSE,
               warning=FALSE)
opts_knit$set(width=75)

library(rgdal)
library(sp)
library(rgeos)
library(dplyr)

```

***

When working with spatial data, one is rarely interested in working with only one source of data. This tutorial will introduce a set of tools for linking vector data with other data sources. It begins by introducing how to link spatial vector data with non-spatial data in table format, then turns to the problem of linking multiple sources of spatial data through spatial joins and intersects.

This tutorial uses the `sp`, `rgdal`, and `raster` libraries from the `RGIS1` tutorial. If you have not yet installed those, please revisit that tutorial for directions. In addition, this tutorial will also make use of the `rgeos` and `plyr` libraries, installation of which is discussed in `part0_setup`.

***

Most geometric operations -- like creating buffers, creating geometric intersections, unions of polygons, etc. -- are executed using the `rgeos` library. Whenever you're thinking about a geometric operation, `rgeos` is the first place to look.

## 1. Installation Instructions

**On Windows**

* 1. `install.packages(c("rgeos", "plyr"))` is usually all you need!

**On Macs**

Installation of the `rgeos` library on Macs can be a little tricky -- as of September 2015, `install.packages("rgeos")` will not work on macs (though hopefully this will change soon?). In the meantime, most people find the following directions works:

* 1. Make sure you have downloaded and installed the [GDAL Complete](http://www.kyngchaos.com/files/software/frameworks/GDAL_Complete-1.11.dmg) library from `RGIS1`.
* 2. Run the following command:
```{r, eval=FALSE}
install.packages("rgeos", type = "source", configure.args ="--with-geos-config=/Library/Frameworks/GEOS.framework/Versions/Current/unix/bin/geos-config")
```
* 3. Test the installation by typing `library(rgeos)`. If it works, you're done!
* 4. If the library fails to load, try the directions on [this site](http://dyerlab.bio.vcu.edu/2015/03/31/install-rgeos-on-osx/)
* 5. Install `plyr` by `install.packages("plyr")`

## 2. Test Installation

To test your installation, just type `library(rgeos)` and `library(plyr)`. If it loads, you're set!

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