ArcGIS to R spatial cheat sheetGet the pdf versionWith thanks to Ross Dwyer for helping out with this one.
We hope you enjoy our cheat sheet for commonly used functions in spatial R packages. Once you are comfortable with R, it very convenient for spatial processing and offers many powerful (and free) statistical packages.
For all functions below xshape is a generic shape (vector) file, xpoly is a polygon shape file, xline is a line shape file, xpoint is a points shape file and xraster is a raster file. Some ARC GIS functions are provided in addon toolboxes, which we have indicated in brackets. We have provided you with some key functions, for more info see the excellent documentation for each package and their vignette’s.
Packages
sp for spatial classes (polygons etc…) raster for raster classes, raster functions and some functions for shapes. rgdal for gdal (projections) rgeos for operations on shapes (e.g. union) geosphere for great circle distances maps for standard maps
Loading and saving files
Load a shapefile
readOGR('.', 'filename') Save a shapefile
writeOGR(xshape, dsn ='dsn', layer = 'layer', driver = 'ESRI Shapefile') Load a raster
raster('filename') Save a raster
writeRaster(xraster, 'filename', format='ascii')
Rasters
Operation 
GIS menu 
R function 
Crop 
Clip/mask 
crop(xraster, xextent) 
Aggregate cells 
Aggregate (Spatial Analyst) 
aggregate(xraster, fact = y) 
Disaggregate cells 
Resample (Data Management) 
disaggregate(xraster, fact = y) 
Change resolution or origin 
Resample (Data Management) 
resample(xraster, yraster) 
Combine two layers 
Raster Calculator (Spatial Analyst) 
overlay(xraster, yraster,fun = xfun) 
Shortest distance 
Euclidean Distance (Spatial Analyst) 
distance(xraster, xextent) 
Distance from a set of points 
Euclidean Distance (Spatial Analyst) 
distanceFromPoints(xraster, xpoints) 
Area of cells 
Tabulate Area (Spatial Analyst) 
area(xraster) 
Summary of values 
Raster Calculator (Spatial Analyst) 
cellStats(xraster, stat='mean') 
Summaries by zones 
Zonal Geometry (Spatial Analyst) 
zonal(xraster,zones.raster, fun='mean') 
Change projection 
Project Raster (Data Management) 
projectRaster(from = xraster, to = yraster, method ='bilinear') 
Shapefiles
Operation 
GIS menu 
R function 
All shapes 
Clip using a rectangle 
Clip 
crop(xpoly) 
Select spatial objects by drawing 
Select 
select(xpoly) 
Clip using a rectangle 
Clip 
click(xpoly) 
Click on map to identify spatial objects 
Identity 
merge(xpoly) 
Combine spatial objects 
Append 
bind(xpoly) 
Query between spatial objects 
Select 
over(xpoly) 
Coordinates at a location 
hover mouse over the location 
locator(1) then click 
Polygons 
Aggregate polygons together 
Dissolve 
aggregate(xpoly) 
Split polygon into separate parts 
Explode 
disaggregate(xpoly) 
Erase parts of a spatial polygon 
Erase 
erase(xpoly) 
Intersection of spatial polygons 
Intersect 
intersect(xpoly) 
Union of spatial polygons 
Union 
union(xpoly) 
Change a spatial polygon by overlaying values from another 
Identity and Update 
cover(xpoly) 
Symmetrical differences of spatial polygons 
Symmetrical Differences 
symdif(xpoly) 
Area of a polygon 
Geometry calculator 
gArea(xpoly) 
Draw a polygon 
Create feature 
drawPoly() then click on figure 
Lines 
Length of a line 
Geometry calculator 
gLength(xline) 
Points 
Distance between points 
Point distance 
gDistance(xpoint, byid=T) 
Combining shapes and rasters
Operation 
GIS menu 
R function 
Make a raster from shape 
PolygonToRaster_conversion 
rasterize(xshape, xraster) 
Make points from a raster 
RasterToPoint_conversion 
rasterToPoints(xraster) 
Make polygons from a raster 
RasterToPolygon_conversion 
rasterToPolygon(xraster) 
Query between spatial objects and rasters 
Sample, Extract by Points, Extract by Polygons (Spatial Analyst) 
extract(xpoly) 
This is an ongoing project, feel free to email us with suggestions. We are keen to improve this cheat sheet, but also keep it simple. Cheers, Chris and Ross

Updating...
Ċ Chris Brown, Mar 11, 2015, 10:30 PM
