## Geospatial Use Cases

## R Analytical Environment

Read and write ESRI Shape Files [1]

Demonstrates techniques from three R packages for reading, displaying, and writing ESRI Shapefiles

Display R Spatial Objects with Google Maps / Google Earth [2]

Demonstrates creation of Keyhole Markup Language (KML) files for vector ESRI Shape Files and raster GeoTIFF files, enabling their display in GoogleEarth / Google Maps

Read and Display Data from GPS Devices Using R [3]

Two examples demonstrate the use of the R environment to process data sets from GPS devices: Read/Translate/Display/Write ASCII Point Files.

Point-in-Polygon Assignment to Point Data Set Members [4]

Associate points in a data set with the polygons in a second data set that surround them

Compute Shortest Path between points in Euclidean Space [5]

Compute a matrix of shortest-path distances between spatially-referenced points in a region

Overlay Points on Satellite Image / Extract Pixel Values [6]

Use R geospatial classes to assign MODIS Image temperature values to georeferenced point locations.

Sampling Vector Polygon Data Using Point Grid Overlay [7]

Overlay a regularly-spaced grid of points on the Bailey's Ecoregions map of the United States, and extract the Bailey's region number underneath each point.

Compute Centroids for a Polygon set [8]

Demonstrates computation of Centroid (Center of Gravity) points for a polygon data set stored in an ESRI Shape File

Compute Convex Hull/Region of Interest Polygons for Point Data Sets [9]

Given a point data set AND a polygon data set whose members surround the point set members: 1) Compute the polygon areas; 2) assign each point its 'bounding polygon'; 3) calculate the convex hull bounding the point data set; 4) generate Region of Interest (ROI) polygons surrounding each point data set member

Explore the relationships of spatially coincident point and polygon data layers using R geospatial tools

Assign Closest Points to members of a separate point data set [11]

Input two geocoded point data sets from .csv files into R workspace, then assign to one data set the closest point locations from the other

Polygon Dissolve Operations [12]

Aggregate spatial data polygons into larger polygons along with their descriptive attributes, using a spatial primary key

Join and Query Relational Data Tables With R [13]

Join and perform relational queries on multiple attribute tables. Compute summary statistics using the joined tables.

Create Maps With R Geospatial Classes and Graphics Tools [14]

Generate various types of publication-quality maps using standard R graphics tools

Cartographical Map Projections: A Discussion [15]

A comprehensive introduction to the art, science, and application of map projections

Integrate C Language Function Into R With an R Package [16]

A step-by-step tutorial, including a complete, downloadable example, demonstrating the creation and use of an R package that calls a C function performing simple matrix calculations

## ESRI ArcMap GIS

ArcMap GIS: Use Mouse to Point/Click/Extract Image Values From Raster Data Layer (12 kb Pdf) [17]

Change the Latitude/Longitude display units and extract single-pixel values using the mouse

ArcMap GIS Overlay Polygon Coverage Generation (33 kb Pdf) [18]

Create a Point Shape File attribute file by performing a series of Spatial Join operations

ESRI ArcMap GIS Spatial Overlay Analysis (31 kb Pdf) [19]

Use Polygon Shape Files to perform raster data set clipping operations

Interactively Extract and Save Arc Map GIS Shape File Subset (9 kb Pdf) [20]

Use the mouse to select and write a subset of existing ESRI Shape File to new Shapefile