GIS Tutorial
Rachel Saidi & Mary Glantz
10/20/2020
This tutorial is part of Computerworld’s How to Make a Map with R
I’ve added a section at the end showing the percentage support for Trump in PA 2016 GOP primaries.
In 10 (fairly) Easy Steps https://www.computerworld.com/article/3038270/data-analytics/create-maps-in-r-in-10-fairly-easy-steps.html by Sharon Machlis sharon_machlis@idg.com
# Set various values needed, including names of files and FIPS codes for New Hampshire and South Carolina
nhdatafile <- "NHD2016.xlsx"
nhdatafilecsv <- "NHD2016.csv"
usshapefile <- "cb_2014_us_county_5m/cb_2014_us_county_5m.shp"
nhfipscode <- "33"
scdatafile <- "SCGOP2016.csv"
scfipscode <- "45"
pafipscode <- "42"Run any of the install.packages() commands below for packages that are not yet on your system
install.packages(“shiny”) install.packages(“urltools”) install.packages(“tmap”) install.packages(“tmaptools”) install.packages(“leaflet”) install.packages(“scales”) install.packages(“leaflet.extras”) install.packages(“rio”) install.packages(“htmlwidgets”) install.packages(“sf”) install.packages(“dplyr”)
Load the tmap, tmaptools, and leaflet packages into your working session:
library(tidyverse)## ── Attaching packages ────────────────────────────────────────────────────────────────────────────────────────────────── tidyverse 1.3.0 ──## ✓ ggplot2 3.3.2 ✓ purrr 0.3.4
## ✓ tibble 3.0.3 ✓ dplyr 1.0.2
## ✓ tidyr 1.1.2 ✓ stringr 1.4.0
## ✓ readr 1.3.1 ✓ forcats 0.5.0## ── Conflicts ───────────────────────────────────────────────────────────────────────────────────────────────────── tidyverse_conflicts() ──
## x dplyr::filter() masks stats::filter()
## x dplyr::lag() masks stats::lag()library(tmap)
library(tmaptools)
library(leaflet)
library(sf)## Linking to GEOS 3.8.1, GDAL 3.1.1, PROJ 6.3.1library(leaflet.extras)
library(dplyr)
library(rio)
library(sp)Step 1: Read in the NH election results file:
setwd("~/Desktop/DATA 110/GIS")
#nhdata <- import(nhdatafile)
nhdata <- import(nhdatafilecsv)If you have any problems with this, there is also a CSV version of the file – sometimes reading Excel between Mac and Windows can be tricky. Try
nhdata <- rio::import(nhdatafilecsv)
Eliminate columns for minor candidates and just use County, Clinton and Sanders columns:
nhdata <- nhdata[,c("County", "Clinton", "Sanders")]Step 2: Decide what data to map
###Add columns for percents and margins:
nhdata$SandersMarginVotes <- nhdata$Sanders - nhdata$Clinton
nhdata$SandersPct <- (nhdata$Sanders) / (nhdata$Sanders + nhdata$Clinton)
# Will use formatting later to multiply by a hundred
nhdata$ClintonPct <- (nhdata$Clinton) / (nhdata$Sanders + nhdata$Clinton)
nhdata$SandersMarginPctgPoints <- nhdata$SandersPct - nhdata$ClintonPctStep 3: Get geographic data files
Read in the shapefile for US states and counties:
If libraries with raster and rgdal don’t work (see next chunk), try library(sf) with the command st_read
All these options are here and should help you get the qtm command in the next chunk
#install.packages("raster")
#install.packages("rgdal")
setwd("~/Desktop/DATA 110/GIS")
library(raster)##
## Attaching package: 'raster'## The following object is masked from 'package:dplyr':
##
## select## The following object is masked from 'package:tidyr':
##
## extractlibrary(rgdal)## rgdal: version: 1.5-18, (SVN revision 1082)
## Geospatial Data Abstraction Library extensions to R successfully loaded
## Loaded GDAL runtime: GDAL 3.1.1, released 2020/06/22
## Path to GDAL shared files: /Library/Frameworks/R.framework/Versions/4.0/Resources/library/rgdal/gdal
## GDAL binary built with GEOS: TRUE
## Loaded PROJ runtime: Rel. 6.3.1, February 10th, 2020, [PJ_VERSION: 631]
## Path to PROJ shared files: /Library/Frameworks/R.framework/Versions/4.0/Resources/library/rgdal/proj
## Linking to sp version:1.4-4
## To mute warnings of possible GDAL/OSR exportToProj4() degradation,
## use options("rgdal_show_exportToProj4_warnings"="none") before loading rgdal.usgeo <- shapefile("cb_2014_us_county_5m/cb_2014_us_county_5m.shp")## Warning in rgdal::readOGR(dirname(x), fn, stringsAsFactors = stringsAsFactors, :
## Z-dimension discardedDo a quick plot (qtm stands for quick thematic map) of the shapefile and check its structure:
qtm(usgeo)
# (pause to wait for map to render, may take a few seconds)
view(usgeo)Subset just the NH data from the US shapefile
nhgeo <- usgeo[usgeo$STATEFP==nhfipscode,]tmap test plot of the New Hampshire data
qtm(nhgeo)
structure of the object
str(nhgeo)## Formal class 'SpatialPolygonsDataFrame' [package "sp"] with 5 slots
## ..@ data :'data.frame': 10 obs. of 9 variables:
## .. ..$ STATEFP : chr [1:10] "33" "33" "33" "33" ...
## .. ..$ COUNTYFP: chr [1:10] "009" "011" "007" "001" ...
## .. ..$ COUNTYNS: chr [1:10] "00873178" "00873179" "00873177" "00873174" ...
## .. ..$ AFFGEOID: chr [1:10] "0500000US33009" "0500000US33011" "0500000US33007" "0500000US33001" ...
## .. ..$ GEOID : chr [1:10] "33009" "33011" "33007" "33001" ...
## .. ..$ NAME : chr [1:10] "Grafton" "Hillsborough" "Coos" "Belknap" ...
## .. ..$ LSAD : chr [1:10] "06" "06" "06" "06" ...
## .. ..$ ALAND : chr [1:10] "4425927252" "2269220216" "4648216798" "1036582289" ...
## .. ..$ AWATER : chr [1:10] "105375486" "41604851" "90773891" "177039345" ...
## ..@ polygons :List of 10
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.8 43.9
## .. .. .. .. .. .. ..@ area : num 0.508
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:327, 1:2] -72.3 -72.3 -72.3 -72.3 -72.3 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.8 43.9
## .. .. .. ..@ ID : chr "685"
## .. .. .. ..@ area : num 0.508
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.7 42.9
## .. .. .. .. .. .. ..@ area : num 0.255
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:45, 1:2] -72.1 -72 -72 -72 -72 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.7 42.9
## .. .. .. ..@ ID : chr "866"
## .. .. .. ..@ area : num 0.255
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.3 44.7
## .. .. .. .. .. .. ..@ area : num 0.539
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:511, 1:2] -71.8 -71.8 -71.8 -71.7 -71.7 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.3 44.7
## .. .. .. ..@ ID : chr "922"
## .. .. .. ..@ area : num 0.539
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.4 43.5
## .. .. .. .. .. .. ..@ area : num 0.136
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:33, 1:2] -71.7 -71.7 -71.7 -71.7 -71.7 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.4 43.5
## .. .. .. ..@ ID : chr "1100"
## .. .. .. ..@ area : num 0.136
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.1 43
## .. .. .. .. .. .. ..@ area : num 0.208
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:123, 1:2] -71.5 -71.4 -71.4 -71.4 -71.4 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.1 43
## .. .. .. ..@ ID : chr "1278"
## .. .. .. ..@ area : num 0.208
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -72.3 42.9
## .. .. .. .. .. .. ..@ area : num 0.208
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:161, 1:2] -72.6 -72.6 -72.6 -72.6 -72.6 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -72.3 42.9
## .. .. .. ..@ ID : chr "1877"
## .. .. .. ..@ area : num 0.208
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71 43.3
## .. .. .. .. .. .. ..@ area : num 0.11
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:177, 1:2] -71.2 -71.2 -71.2 -71.2 -71.1 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71 43.3
## .. .. .. ..@ ID : chr "2676"
## .. .. .. ..@ area : num 0.11
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.7 43.3
## .. .. .. .. .. .. ..@ area : num 0.274
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:49, 1:2] -72.1 -72.1 -72 -72.1 -72.1 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.7 43.3
## .. .. .. ..@ ID : chr "2773"
## .. .. .. ..@ area : num 0.274
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.2 43.9
## .. .. .. .. .. .. ..@ area : num 0.288
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:73, 1:2] -71.6 -71.4 -71.4 -71.3 -71.4 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.2 43.9
## .. .. .. ..@ ID : chr "3077"
## .. .. .. ..@ area : num 0.288
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -72.2 43.4
## .. .. .. .. .. .. ..@ area : num 0.159
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:118, 1:2] -72.5 -72.4 -72.4 -72.4 -72.4 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -72.2 43.4
## .. .. .. ..@ ID : chr "3167"
## .. .. .. ..@ area : num 0.159
## ..@ plotOrder : int [1:10] 3 1 9 8 2 6 5 10 4 7
## ..@ bbox : num [1:2, 1:2] -72.6 42.7 -70.7 45.3
## .. ..- attr(*, "dimnames")=List of 2
## .. .. ..$ : chr [1:2] "x" "y"
## .. .. ..$ : chr [1:2] "min" "max"
## ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slot
## .. .. ..@ projargs: chr "+proj=longlat +datum=NAD83 +no_defs"# Check if county names are in the same format in both files
str(nhgeo$NAME)## chr [1:10] "Grafton" "Hillsborough" "Coos" "Belknap" "Rockingham" ...str(nhdata$County)## chr [1:10] "Belknap" "Carroll" "Cheshire" "Coos" "Grafton" "Hillsborough" ...# They're not. Change the county names to plain characters in nhgeo:
nhgeo$NAME <- as.character(nhgeo$NAME)Order each data set by county name
nhgeo <- nhgeo[order(nhgeo$NAME),]
nhdata <- nhdata[order(nhdata$County),]
# Are the two county columns identical now? They should be:
identical(nhgeo$NAME,nhdata$County)## [1] TRUEStep 4: Merge geo data with results data using the merge function
library(sf)
nhmap <- merge(nhgeo, nhdata, by.x = "NAME", by.y = "County")# See the new data structure with
str(nhmap)## Formal class 'SpatialPolygonsDataFrame' [package "sp"] with 5 slots
## ..@ data :'data.frame': 10 obs. of 15 variables:
## .. ..$ NAME : chr [1:10] "Belknap" "Carroll" "Cheshire" "Coos" ...
## .. ..$ STATEFP : chr [1:10] "33" "33" "33" "33" ...
## .. ..$ COUNTYFP : chr [1:10] "001" "003" "005" "007" ...
## .. ..$ COUNTYNS : chr [1:10] "00873174" "00873175" "00873176" "00873177" ...
## .. ..$ AFFGEOID : chr [1:10] "0500000US33001" "0500000US33003" "0500000US33005" "0500000US33007" ...
## .. ..$ GEOID : chr [1:10] "33001" "33003" "33005" "33007" ...
## .. ..$ LSAD : chr [1:10] "06" "06" "06" "06" ...
## .. ..$ ALAND : chr [1:10] "1036582289" "2411458935" "1830366195" "4648216798" ...
## .. ..$ AWATER : chr [1:10] "177039345" "158933434" "57990901" "90773891" ...
## .. ..$ Clinton : int [1:10] 3495 3230 5132 2013 6918 28147 12250 22829 8813 2497
## .. ..$ Sanders : int [1:10] 6005 5638 12441 3639 14245 39245 18107 31065 15881 5915
## .. ..$ SandersMarginVotes : int [1:10] 2510 2408 7309 1626 7327 11098 5857 8236 7068 3418
## .. ..$ SandersPct : num [1:10] 0.632 0.636 0.708 0.644 0.673 ...
## .. ..$ ClintonPct : num [1:10] 0.368 0.364 0.292 0.356 0.327 ...
## .. ..$ SandersMarginPctgPoints: num [1:10] 0.264 0.272 0.416 0.288 0.346 ...
## ..@ polygons :List of 10
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.4 43.5
## .. .. .. .. .. .. ..@ area : num 0.136
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:33, 1:2] -71.7 -71.7 -71.7 -71.7 -71.7 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.4 43.5
## .. .. .. ..@ ID : chr "1100"
## .. .. .. ..@ area : num 0.136
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.2 43.9
## .. .. .. .. .. .. ..@ area : num 0.288
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:73, 1:2] -71.6 -71.4 -71.4 -71.3 -71.4 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.2 43.9
## .. .. .. ..@ ID : chr "3077"
## .. .. .. ..@ area : num 0.288
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -72.3 42.9
## .. .. .. .. .. .. ..@ area : num 0.208
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:161, 1:2] -72.6 -72.6 -72.6 -72.6 -72.6 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -72.3 42.9
## .. .. .. ..@ ID : chr "1877"
## .. .. .. ..@ area : num 0.208
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.3 44.7
## .. .. .. .. .. .. ..@ area : num 0.539
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:511, 1:2] -71.8 -71.8 -71.8 -71.7 -71.7 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.3 44.7
## .. .. .. ..@ ID : chr "922"
## .. .. .. ..@ area : num 0.539
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.8 43.9
## .. .. .. .. .. .. ..@ area : num 0.508
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:327, 1:2] -72.3 -72.3 -72.3 -72.3 -72.3 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.8 43.9
## .. .. .. ..@ ID : chr "685"
## .. .. .. ..@ area : num 0.508
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.7 42.9
## .. .. .. .. .. .. ..@ area : num 0.255
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:45, 1:2] -72.1 -72 -72 -72 -72 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.7 42.9
## .. .. .. ..@ ID : chr "866"
## .. .. .. ..@ area : num 0.255
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.7 43.3
## .. .. .. .. .. .. ..@ area : num 0.274
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:49, 1:2] -72.1 -72.1 -72 -72.1 -72.1 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.7 43.3
## .. .. .. ..@ ID : chr "2773"
## .. .. .. ..@ area : num 0.274
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71.1 43
## .. .. .. .. .. .. ..@ area : num 0.208
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:123, 1:2] -71.5 -71.4 -71.4 -71.4 -71.4 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71.1 43
## .. .. .. ..@ ID : chr "1278"
## .. .. .. ..@ area : num 0.208
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -71 43.3
## .. .. .. .. .. .. ..@ area : num 0.11
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:177, 1:2] -71.2 -71.2 -71.2 -71.2 -71.1 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -71 43.3
## .. .. .. ..@ ID : chr "2676"
## .. .. .. ..@ area : num 0.11
## .. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
## .. .. .. ..@ Polygons :List of 1
## .. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
## .. .. .. .. .. .. ..@ labpt : num [1:2] -72.2 43.4
## .. .. .. .. .. .. ..@ area : num 0.159
## .. .. .. .. .. .. ..@ hole : logi FALSE
## .. .. .. .. .. .. ..@ ringDir: int 1
## .. .. .. .. .. .. ..@ coords : num [1:118, 1:2] -72.5 -72.4 -72.4 -72.4 -72.4 ...
## .. .. .. ..@ plotOrder: int 1
## .. .. .. ..@ labpt : num [1:2] -72.2 43.4
## .. .. .. ..@ ID : chr "3167"
## .. .. .. ..@ area : num 0.159
## ..@ plotOrder : int [1:10] 4 5 2 7 6 3 8 10 1 9
## ..@ bbox : num [1:2, 1:2] -72.6 42.7 -70.7 45.3
## .. ..- attr(*, "dimnames")=List of 2
## .. .. ..$ : chr [1:2] "x" "y"
## .. .. ..$ : chr [1:2] "min" "max"
## ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slot
## .. .. ..@ projargs: chr "+proj=longlat +datum=NAD83 +no_defs"Step 5: Create a static map with tmap’s qtm() function:
qtm(nhmap, "SandersMarginVotes")## Some legend labels were too wide. These labels have been resized to 0.63, 0.63, 0.63, 0.58, 0.54. Increase legend.width (argument of tm_layout) to make the legend wider and therefore the labels larger.
qtm(nhmap, "SandersMarginPctgPoints")
For more control over look and feel, use the tm_shape() function:
tm_shape(nhmap) +
tm_fill("SandersMarginVotes", title="Sanders Margin, Total Votes", palette = "PRGn") +
tm_borders(alpha=.5) +
tm_text("NAME", size=0.8)## Warning in sp::proj4string(obj): CRS object has comment, which is lost in output## Some legend labels were too wide. These labels have been resized to 0.63, 0.63, 0.63, 0.58, 0.54. Increase legend.width (argument of tm_layout) to make the legend wider and therefore the labels larger.
Same code as above, but store the static map in a variable, and change the theme to “classic” style:
nhstaticmap <- tm_shape(nhmap) +
tm_fill("SandersMarginVotes", title="Sanders Margin, Total Votes", palette = "viridis") + #I like viridis
tm_borders(alpha=.5) +
tm_text("NAME", size=0.8) +
tm_style("classic")View the map
nhstaticmap## Warning in sp::proj4string(obj): CRS object has comment, which is lost in output## Some legend labels were too wide. These labels have been resized to 0.63, 0.63, 0.63, 0.58, 0.54. Increase legend.width (argument of tm_layout) to make the legend wider and therefore the labels larger.
save the map to a jpg file with tmap’s tmap_save():
tmap_save(nhstaticmap, filename="nhdemprimary.jpg") ## Warning in sp::proj4string(obj): CRS object has comment, which is lost in output
## Warning in sp::proj4string(obj): CRS object has comment, which is lost in output## Map saved to /Users/maryglantz/Desktop/DATA 110/nhdemprimary.jpg## Resolution: 1501.336 by 2937.385 pixels## Size: 5.004452 by 9.791282 inches (300 dpi)Part 6
Next up: Code for a basic interactive map, this time for Clinton percentages in NH
Create a palette
clintonPalette <- colorNumeric(palette = "Blues", domain=nhmap$ClintonPct)and a pop-up window
library(scales)##
## Attaching package: 'scales'## The following object is masked from 'package:purrr':
##
## discard## The following object is masked from 'package:readr':
##
## col_factorlibrary(raster)
nhpopup <- paste0("County: ", nhmap$County,
"Sanders ", percent(nhmap$SandersPct), " - Clinton ", percent(nhmap$ClintonPct))Step 7: Now generate the interactive map:
# re-project
nhmap_projected <- sp::spTransform(nhmap, "+proj=longlat +datum=WGS84")
leaflet(nhmap_projected) %>%
addProviderTiles("CartoDB.Positron") %>%
addPolygons(stroke=FALSE,
smoothFactor = 0.2,
fillOpacity = .8,
popup=nhpopup,
color= ~clintonPalette(nhmap$ClintonPct)
)South Carolina data
setwd("~/Desktop/DATA 110/GIS")
scdata <- rio::import(scdatafile)South Carolina shapefile and Quick plot of scgeo SC geospatial object:
scgeo <- usgeo[usgeo@data$STATEFP=="45",]
qtm(scgeo)
Add a column with percent of votes for each candidate. Candidates are in columns 2-7:
candidates <- colnames(scdata[2:7])
for(i in 2:7){
j = i + 7
temp <- scdata[[i]] / scdata$Total
scdata[[j]] <- temp
colnames(scdata)[j] <- paste0(colnames(scdata)[i], "Pct")
}
winner <- colnames(scdata[2:7])Get winner in each precinct
for(i in 1:nrow(scdata)){
scdata$winner[i] <- names(which.max(scdata[i,2:7]))
}Import spreadsheet with percent of adult population holding at least a 4-yr college degree
setwd("~/Desktop/DATA 110/GIS")
sced <- rio::import("SCdegree.xlsx")Check if county names are in the same format in both files
str(scgeo$NAME)## chr [1:46] "Edgefield" "Lee" "Horry" "Allendale" "Marion" "Dorchester" ...str(scdata$County)## chr [1:46] "Abbeville" "Aiken" "Allendale" "Anderson" "Bamberg" "Barnwell" ...# Change the county names to plain characters in scgeo:
scgeo$NAME <- as.character(scgeo$NAME)
# Order each data set by county name
scgeo <- scgeo[order(scgeo$NAME),]
scdata <- scdata[order(scdata$County),]
# Are the two county columns identical now? They should be:
identical(scgeo$NAME,scdata$County )## [1] TRUEAdd the election results and rename county column
scmap <- merge(scgeo, scdata, by.x = "NAME", by.y = "County") Instead of just coloring the winner, let’s color by strength of win with multiple layers
# Use same intensity for all - get minimum and maximum for the top 3 combined
minpct <- min(c(scdata$`Donald J TrumpPct`, scdata$`Marco RubioPct`, scdata$`Ted CruzPct`))
maxpct <- max(c(scdata$`Donald J TrumpPct`, scdata$`Marco RubioPct`, scdata$`Ted CruzPct`))Create leaflet palettes for each layer of the map:
trumpPalette <- colorNumeric(palette = "Purples", domain=c(minpct, maxpct))
rubioPalette <- colorNumeric(palette = "Reds", domain = c(minpct, maxpct))
cruzPalette <- colorNumeric(palette = "Oranges", domain = c(minpct, maxpct))
winnerPalette <- colorFactor(palette=c("#984ea3", "#e41a1c"), domain = scmap$winner)
edPalette <- colorNumeric(palette = "Blues", domain=scmap$PctCollegeDegree)Create a pop-up:
scpopup <- paste0("<b>County: ", scmap$County, "<br />Winner: ", scmap$winner, "</b><br /><br />Trump: ", percent(scmap$`Donald J TrumpPct`), "<br />Rubio: ", percent(scmap$`Marco RubioPct`), "<br />Cruz: ", percent(scmap$`Ted CruzPct`), "<br /><br />Pct w college ed: ", sced$PctCollegeDegree, "% vs state-wide avg of 25%")Add the projection we know from the NH map we’ll need for this data on a Leaflet map:
scmap <- sp::spTransform(scmap, "+proj=longlat +datum=WGS84")Basic interactive map showing winner in each county:
leaflet(scmap) %>%
addProviderTiles("CartoDB.Positron") %>%
addPolygons(stroke=TRUE,
weight=1,
smoothFactor = 0.2,
fillOpacity = .75,
popup=scpopup,
color= ~winnerPalette(scmap$winner),
group="Winners" ) %>%
addLegend(position="bottomleft", colors=c("#984ea3", "#e41a1c"), labels=c("Trump", "Rubio"))Put top 3 candidates in their own layers and add education layer, store in scGOPmap2 variable
scGOPmap <- leaflet(scmap) %>%
addProviderTiles("CartoDB.Positron") %>%
addPolygons(stroke=TRUE,
weight=1,
smoothFactor = 0.2,
fillOpacity = .75,
popup=scpopup,
color= ~winnerPalette(scmap$winner),
group="Winners" ) %>%
addLegend(position="bottomleft", colors=c("#984ea3", "#e41a1c"), labels=c("Trump", "Rubio")) %>%
addPolygons(stroke=TRUE,
weight=1,
smoothFactor = 0.2,
fillOpacity = .75,
popup=scpopup,
color= ~trumpPalette(scmap$`Donald J TrumpPct`),
group="Trump") %>%
addPolygons(stroke=TRUE,
weight=1,
smoothFactor = 0.2,
fillOpacity = .75,
popup=scpopup,
color= ~rubioPalette(scmap$`Marco RubioPct`),
group="Rubio") %>%
addPolygons(stroke=TRUE,
weight=1,
smoothFactor = 0.2,
fillOpacity = .75,
popup=scpopup,
color= ~cruzPalette(scmap$`Ted CruzPct`),
group="Cruz") %>%
addPolygons(stroke=TRUE,
weight=1,
smoothFactor = 0.2,
fillOpacity = .75,
popup=scpopup,
color= ~edPalette(sced$PctCollegeDegree), #this data is in the sced table, not scmaps
group="College degs") %>%
addLayersControl(
baseGroups=c("Winners", "Trump", "Rubio", "Cruz", "College degs"),
position = "bottomleft",
options = layersControlOptions(collapsed = FALSE))
# Now display the map
scGOPmapsave as a self-contained HTML file
#htmlwidgets::saveWidget(scGOPmap2, file="scGOPwidget2.html")
# save as an HTML file with dependencies in another directory:
#htmlwidgets::saveWidget(widget=scGOPmap2, file="scGOPprimary_withdependencies.html", selfcontained=FALSE, libdir = "js")Subset just the PA data from the US shapefile
pageo <- usgeo[usgeo$STATEFP==pafipscode,]Display the map
qtm(pageo)
Read in 2016 primary data file (from kaggle)
setwd("~/Desktop/DATA 110/GIS")
usa_data <- read_csv("primary_results.csv")## Parsed with column specification:
## cols(
## state = col_character(),
## state_abbreviation = col_character(),
## county = col_character(),
## fips = col_double(),
## party = col_character(),
## candidate = col_character(),
## votes = col_double(),
## fraction_votes = col_double()
## )select only the PA and republican results
pa_republican <- usa_data %>%
filter(state == "Pennsylvania", party == "Republican")
pa_republican## # A tibble: 201 x 8
## state state_abbreviati… county fips party candidate votes fraction_votes
## <chr> <chr> <chr> <dbl> <chr> <chr> <dbl> <dbl>
## 1 Pennsy… PA Adams 42001 Repub… Donald T… 9754 0.573
## 2 Pennsy… PA Adams 42001 Repub… John Kas… 2687 0.158
## 3 Pennsy… PA Adams 42001 Repub… Ted Cruz 4058 0.239
## 4 Pennsy… PA Allegh… 42003 Repub… Donald T… 61004 0.51
## 5 Pennsy… PA Allegh… 42003 Repub… John Kas… 33045 0.276
## 6 Pennsy… PA Allegh… 42003 Repub… Ted Cruz 23883 0.2
## 7 Pennsy… PA Armstr… 42005 Repub… Donald T… 7578 0.672
## 8 Pennsy… PA Armstr… 42005 Repub… John Kas… 1309 0.116
## 9 Pennsy… PA Armstr… 42005 Repub… Ted Cruz 2154 0.191
## 10 Pennsy… PA Beaver 42007 Repub… Donald T… 11178 0.575
## # … with 191 more rows# Check if county names are in the same format in both files
str(pageo$NAME)## chr [1:67] "Susquehanna" "Lebanon" "Adams" "Potter" "Elk" "Forest" ...str(pa_republican$county)## chr [1:201] "Adams" "Adams" "Adams" "Allegheny" "Allegheny" "Allegheny" ...pageo <- pageo[order(pageo$NAME),]
pa_republican <- pa_republican[order(pa_republican$county),]identical(pageo$NAME, pa_republican$county)## [1] FALSEThere are too many counties in the primary results data because it is long rather than wide
I can’t figure out how to easily convert the data, so since I’m only trying to practice the mapping, I’m going to eliminate anything but Trump’s results
pa_trump <- pa_republican %>% filter(candidate == "Donald Trump")
head(pa_trump)## # A tibble: 6 x 8
## state state_abbreviati… county fips party candidate votes fraction_votes
## <chr> <chr> <chr> <dbl> <chr> <chr> <dbl> <dbl>
## 1 Pennsyl… PA Adams 42001 Repub… Donald T… 9754 0.573
## 2 Pennsyl… PA Allegh… 42003 Repub… Donald T… 61004 0.51
## 3 Pennsyl… PA Armstr… 42005 Repub… Donald T… 7578 0.672
## 4 Pennsyl… PA Beaver 42007 Repub… Donald T… 11178 0.575
## 5 Pennsyl… PA Bedford 42009 Repub… Donald T… 6540 0.631
## 6 Pennsyl… PA Berks 42011 Repub… Donald T… 28719 0.598compare the counties
pageo <- pageo[order(pageo$NAME),]
pa_trump <- pa_trump[order(pa_trump$county),]identical(pageo, pa_trump)## [1] FALSEstill not equal. why?
str(pageo$NAME)## chr [1:67] "Adams" "Allegheny" "Armstrong" "Beaver" "Bedford" "Berks" ...str(pa_trump$county)## chr [1:67] "Adams" "Allegheny" "Armstrong" "Beaver" "Bedford" "Berks" ...Hmmm…this is puzzling. they look exactly the same
Oh wait, maybe it’s because I’m not just checking the counties
identical(pageo$NAME, pa_trump$county)## [1] TRUEOkay, they are exactly the same now.
Add the election results and rename county column
pamap <- merge(pageo, pa_trump, by.x = "NAME", by.y = "county")
head(pamap)## NAME STATEFP COUNTYFP COUNTYNS AFFGEOID GEOID LSAD ALAND
## 1 Adams 42 001 01213656 0500000US42001 42001 06 1343399890
## 2 Allegheny 42 003 01213657 0500000US42003 42003 06 1890887553
## 3 Armstrong 42 005 01213658 0500000US42005 42005 06 1691786942
## 4 Beaver 42 007 01214112 0500000US42007 42007 06 1125901091
## 5 Bedford 42 009 01209171 0500000US42009 42009 06 2621836477
## 6 Berks 42 011 01209172 0500000US42011 42011 06 2218272195
## AWATER state state_abbreviation fips party candidate votes
## 1 7883949 Pennsylvania PA 42001 Republican Donald Trump 9754
## 2 37413758 Pennsylvania PA 42003 Republican Donald Trump 61004
## 3 27556895 Pennsylvania PA 42005 Republican Donald Trump 7578
## 4 24165978 Pennsylvania PA 42007 Republican Donald Trump 11178
## 5 11935904 Pennsylvania PA 42009 Republican Donald Trump 6540
## 6 24025107 Pennsylvania PA 42011 Republican Donald Trump 28719
## fraction_votes
## 1 0.573
## 2 0.510
## 3 0.672
## 4 0.575
## 5 0.631
## 6 0.598Instead of just coloring the winner (since we’ve eliminated everyone but Trump), let’s color by strength of support with multiple layers
minpct <- min(c(pa_trump$fraction_votes))
maxpct <- max(c(pa_trump$fraction_votes))Create leaflet palettes for each layer of the map:
trumpPalette <- colorBin(palette = "Purples", domain = c(minpct, maxpct))Add the projection we know from the NH map we’ll need for this data on a Leaflet map:
pamap <- sp::spTransform(pamap, "+proj=longlat +datum=WGS84")Basic interactive map showing Trump percent in each county:
leaflet(pamap) %>%
addProviderTiles("CartoDB.Positron") %>%
addPolygons(stroke=TRUE,
weight=1,
smoothFactor = 0.2,
fillOpacity = .75,
color= ~trumpPalette(pamap$fraction_votes),
group="Winners" ) %>%
addLegend(position="bottomleft", colors=c("#984ea3"), labels=c("Trump Percentage"))paGOPmap <- leaflet(pamap) %>%
addProviderTiles("CartoDB.Positron") %>%
addPolygons(stroke=TRUE,
weight=1,
smoothFactor = 0.2,
fillOpacity = .75,
popup=scpopup,
color= ~trumpPalette(pamap$fraction_votes),
group="Trump" )
# Now display the map
paGOPmap