devtools::install_github
## Error in get(genname, envir = envir) : object 'testthat_print' not found
## function (repo, ref = "HEAD", subdir = NULL, auth_token = github_pat(quiet), 
##     host = "api.github.com", dependencies = NA, upgrade = c("default", 
##         "ask", "always", "never"), force = FALSE, quiet = FALSE, 
##     build = TRUE, build_opts = c("--no-resave-data", "--no-manual", 
##         "--no-build-vignettes"), build_manual = FALSE, build_vignettes = FALSE, 
##     repos = getOption("repos"), type = getOption("pkgType"), 
##     ...) 
## pkgbuild::with_build_tools({
##     ellipsis::check_dots_used(action = getOption("devtools.ellipsis_action", 
##         rlang::warn))
##     {
##         remotes <- lapply(repo, github_remote, ref = ref, subdir = subdir, 
##             auth_token = auth_token, host = host)
##         install_remotes(remotes, auth_token = auth_token, host = host, 
##             dependencies = dependencies, upgrade = upgrade, force = force, 
##             quiet = quiet, build = build, build_opts = build_opts, 
##             build_manual = build_manual, build_vignettes = build_vignettes, 
##             repos = repos, type = type, ...)
##     }
## }, required = FALSE)
## <bytecode: 0x7f9652dc34a8>
## <environment: namespace:remotes>
remotes::install_github("r-spatial/mapview")
## Skipping install of 'mapview' from a github remote, the SHA1 (b96de520) has not changed since last install.
##   Use `force = TRUE` to force installation
library(mapview)
library(sf)
## Linking to GEOS 3.8.1, GDAL 3.1.4, PROJ 6.3.1
library(censusxy)
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
library(readxl)
satxgroc <- read_excel("/Users/rhl548/Desktop/Cosas/rmd/IPUMS International/satxgroc.xlsx")
## New names:
## * Source -> Source...1
## * Source -> Source...18
addr<-satxgroc[c(6, 7:9)]
names(addr)<-c("street", "city", "st", "zip")
head(addr)
## # A tibble: 6 x 4
##   street                     city        st      zip
##   <chr>                      <chr>       <chr> <dbl>
## 1 646 S Flores St            San Antonio TX    78204
## 2 11122 Nacogdoches Rd       San Antonio TX    78217
## 3 1314 Fredericksburg Rd     San Antonio TX    78201
## 4 1545 S San Marcos          San Antonio TX    78207
## 5 340 Enrique M Barrera Pkwy San Antonio TX    78237
## 6 1430 Austin Hwy            San Antonio TX    78209
results<-cxy_geocode(addr,
                     street = "street",
                     city = "city",
                     state ="st",
                     zip = "zip",
                     class="sf",
                     output = "simple")
## 141 rows removed to create an sf object. These were addresses that the geocoder could not match.
results.proj<-st_transform(results,
                           crs = 2278)
mapview(results.proj)

mean feature - average of coordinates

mean_feature<-apply(st_coordinates(results.proj), MARGIN = 2, FUN = mean)
mean_feature<-data.frame(place="meanfeature", x=mean_feature[1], y= mean_feature[2])
mean_feature<-st_as_sf(mean_feature, coords = c("x", "y"), crs= 2278)

mapview(mean_feature, col.regions="red")+mapview( results)

Central feature - Median of coordinates

median_feature<-apply(st_coordinates(results.proj), MARGIN = 2, FUN = median)
median_feature<-data.frame(place="medianfeature", x=median_feature[1], y= median_feature[2])
median_feature<-st_as_sf(median_feature, coords = c("x", "y"), crs= 2278)

mapview(median_feature, col.regions="green")+
  mapview(mean_feature, col.regions="red")+
  mapview( results)

Buffer points

grocbuff<- st_buffer(results.proj, dist = 2500)
mapview(grocbuff)+mapview(results.proj, col.regions="green")

Convex hull plot

chull <- st_convex_hull(st_union(results))
## although coordinates are longitude/latitude, st_union assumes that they are planar
mapview(chull)+
  mapview(results, col.regions = "green")

kernel density - You need projected data for this to work right

R can do kernel density maps, but using simple features it’s kind of complicated. I will use Qgis through R instead using the qgisprocess package

library(qgisprocess)
## Using 'qgis_process' at '/Applications/QGIS.app/Contents/MacOS/bin/qgis_process'.
## Run `qgis_configure()` for details.
qgis_configure()
## getOption('qgisprocess.path') was not found.
## Sys.getenv('R_QGISPROCESS_PATH') was not found.
## Trying 'qgis_process' on PATH
## Error in rethrow_call(c_processx_exec, command, c(command, args), stdin, : cannot start processx process 'qgis_process' (system error 2, No such file or directory) @unix/processx.c:592 (processx_exec)
## Found 1 QGIS installation containing 'qgis_process':
##  /Applications/QGIS.app/Contents/MacOS/bin/qgis_process
## Trying command '/Applications/QGIS.app/Contents/MacOS/bin/qgis_process'
## Success!

To use this, we need to find the name of the Qgis algorithm we want. qgis_algorithms() can return all available algorithms, then we can either filter it with View() or use grep to search for one.

algs<-qgis_algorithms()
algs[grepl(pattern = "density", x = algs$algorithm ),]
## # A tibble: 8 x 5
##   provider provider_title  algorithm       algorithm_id     algorithm_title     
##   <chr>    <chr>           <chr>           <chr>            <chr>               
## 1 grass7   GRASS           grass7:r.li.ed… r.li.edgedensity r.li.edgedensity    
## 2 grass7   GRASS           grass7:r.li.ed… r.li.edgedensit… r.li.edgedensity.as…
## 3 grass7   GRASS           grass7:r.li.pa… r.li.patchdensi… r.li.patchdensity   
## 4 grass7   GRASS           grass7:r.li.pa… r.li.patchdensi… r.li.patchdensity.a…
## 5 native   QGIS (native c… native:lineden… linedensity      Line density        
## 6 qgis     QGIS            qgis:heatmapke… heatmapkernelde… Heatmap (Kernel Den…
## 7 saga     SAGA            saga:fragmenta… fragmentationcl… Fragmentation class…
## 8 saga     SAGA            saga:kernelden… kerneldensityes… Kernel density esti…
qgis_show_help("qgis:heatmapkerneldensityestimation")
## Heatmap (Kernel Density Estimation) (qgis:heatmapkerneldensityestimation)
## 
## ----------------
## Description
## ----------------
## 
## ----------------
## Arguments
## ----------------
## 
## INPUT: Point layer
##  Argument type:  source
##  Acceptable values:
##      - Path to a vector layer
## RADIUS: Radius
##  Argument type:  distance
##  Acceptable values:
##      - A numeric value
## RADIUS_FIELD: Radius from field
##  Argument type:  field
##  Acceptable values:
##      - The name of an existing field
##      - ; delimited list of existing field names
## PIXEL_SIZE: Output raster size
##  Argument type:  number
##  Acceptable values:
##      - A numeric value
## WEIGHT_FIELD: Weight from field
##  Argument type:  field
##  Acceptable values:
##      - The name of an existing field
##      - ; delimited list of existing field names
## KERNEL: Kernel shape
##  Argument type:  enum
##  Available values:
##      - 0: Quartic
##      - 1: Triangular
##      - 2: Uniform
##      - 3: Triweight
##      - 4: Epanechnikov
##  Acceptable values:
##      - Number of selected option, e.g. '1'
##      - Comma separated list of options, e.g. '1,3'
## DECAY: Decay ratio (Triangular kernels only)
##  Argument type:  number
##  Acceptable values:
##      - A numeric value
## OUTPUT_VALUE: Output value scaling
##  Argument type:  enum
##  Available values:
##      - 0: Raw
##      - 1: Scaled
##  Acceptable values:
##      - Number of selected option, e.g. '1'
##      - Comma separated list of options, e.g. '1,3'
## OUTPUT: Heatmap
##  Argument type:  rasterDestination
##  Acceptable values:
##      - Path for new raster layer
## 
## ----------------
## Outputs
## ----------------
## 
## OUTPUT: <outputRaster>
##  Heatmap

Run the algorithm

groc_dens<-qgis_run_algorithm(algorithm ="qgis:heatmapkerneldensityestimation",
         INPUT=results.proj,
         RADIUS = 5000,
         PIXEL_SIZE = 100,
         KERNEL = 0,
         OUTPUT=file.path(getwd(), "grocdenst.TIF"),
         load_output = TRUE)
## Running /Applications/QGIS.app/Contents/MacOS/bin/qgis_process run \
##   'qgis:heatmapkerneldensityestimation' \
##   '--INPUT=/var/folders/_1/tkj8dh2n73s3c5fp80h0td380000gn/T//RtmpYVQfSd/filec1ea341d06a1/filec1ea71865750.gpkg' \
##   '--RADIUS=5000' '--PIXEL_SIZE=100' '--KERNEL=0' '--OUTPUT_VALUE=0' \
##   '--OUTPUT=/Users/rhl548/Desktop/Cosas/rmd/screenshots/grocdenst.TIF'
## 
## ----------------
## Inputs
## ----------------
## 
## INPUT:   /var/folders/_1/tkj8dh2n73s3c5fp80h0td380000gn/T//RtmpYVQfSd/filec1ea341d06a1/filec1ea71865750.gpkg
## KERNEL:  0
## OUTPUT:  /Users/rhl548/Desktop/Cosas/rmd/screenshots/grocdenst.TIF
## OUTPUT_VALUE:    0
## PIXEL_SIZE:  100
## RADIUS:  5000
## 
## 
## 0...10...20...30...40...50...60...70...80...90...
## ----------------
## Results
## ----------------
## 
## OUTPUT:  /Users/rhl548/Desktop/Cosas/rmd/screenshots/grocdenst.TIF
library(raster)
library(RColorBrewer)

result<- qgis_as_raster(groc_dens)

projection(result)<-crs(results.proj)
mapview(result)+mapview(results.proj)

Spatial join

A spatial join can combine attributes of one layer with another layer. Here I combine census variables with the groc clinic points.

library(tidycensus)
library(dplyr)
#load census tract data
sa_acs<-get_acs(geography = "tract",
                state="TX",
                county = "Bexar", 
                year = 2019,
                variables=c( "DP05_0001E", "DP03_0009P", "DP03_0062E", "DP03_0119PE",
                           "DP05_0001E","DP02_0009PE","DP02_0008PE","DP02_0040E","DP02_0038E",
                            "DP02_0066PE","DP02_0067PE","DP02_0080PE","DP02_0092PE",
                        "DP03_0005PE","DP03_0028PE","DP03_0062E","DP03_0099PE","DP03_0101PE",
                            "DP03_0119PE","DP04_0046PE","DP05_0072PE","DP05_0073PE",
                            "DP05_0066PE", "DP05_0072PE", "DP02_0113PE") ,
                geometry = T, output = "wide")
## Getting data from the 2015-2019 5-year ACS
## Downloading feature geometry from the Census website.  To cache shapefiles for use in future sessions, set `options(tigris_use_cache = TRUE)`.
## Using the ACS Data Profile
## Using the ACS Data Profile
#rename variables and filter missing cases
sa_acs2<-sa_acs%>%
  mutate(totpop= DP05_0001E, pwhite=DP05_0072PE, 
         pblack=DP05_0073PE , phisp=DP05_0066PE,
         phsormore=DP02_0066PE,punemp=DP03_0009PE, medhhinc=DP03_0062E,
         ppov=DP03_0119PE)%>%
  dplyr::select(GEOID, totpop, pblack, pwhite, phisp, punemp, medhhinc, ppov)

sa_acs2<-st_transform(sa_acs2, crs = 2278)
sa_trol<-st_cast(sa_acs2, "MULTILINESTRING")
spjoin<-st_join(results.proj, sa_acs2)
head(spjoin)
## Simple feature collection with 6 features and 12 fields
## Geometry type: POINT
## Dimension:     XY
## Bounding box:  xmin: 2100083 ymin: 13676720 xmax: 2147585 ymax: 13769830
## Projected CRS: NAD83 / Texas South Central (ftUS)
##                        street        city st   zip       GEOID totpop pblack
## 386           646 S Flores St San Antonio TX 78204 48029192100   2299    0.7
## 83            1430 Austin Hwy San Antonio TX 78209 48029120600   5850    1.4
## 97         1515 N Loop 1604 E San Antonio TX 78232 48029191817  12785    1.7
## 311          5025 Nw Loop 410 San Antonio TX 78229 48029180702   6892    0.8
## 457 8500 Jones Maltsberger Rd San Antonio TX 78216 48029120701   6416    3.1
## 36        1200 Se Military Dr San Antonio TX 78214 48029192200   2790    1.3
##     pwhite phisp punemp medhhinc ppov                 geometry
## 386   42.4   0.0    3.8    73194  1.2 POINT (2128476 13699880)
## 83    24.5   0.7    6.2    54279  7.9 POINT (2147585 13726925)
## 97    34.2   0.3    5.6    98311  3.5 POINT (2136320 13769833)
## 311   45.6   0.1    8.0    37899 19.6 POINT (2100083 13725095)
## 457   47.2   1.6    7.0    51633  6.3 POINT (2132875 13735344)
## 36    60.4   1.3    5.8    41623 12.5 POINT (2134829 13676718)
mapview(spjoin["punemp"])+mapview(sa_trol)

Count points in polygons

Point in polygon operations are actually a spatial intersection (more on this next week!) where we see how many points fall within a given polygon.

sa_acs2$ngroc<- lengths(st_intersects(sa_acs2, results.proj))
mapview(sa_acs2, zcol="ngroc")+
  mapview(results.proj, col.regions = "green")

Thiessen/Voronoi Polygons

Thiessen or Voronoi polygons are a process where we can convert points into polygons.

algs[grepl(pattern = "voronoi", x = algs$algorithm ),]
## # A tibble: 3 x 5
##   provider provider_title algorithm            algorithm_id     algorithm_title 
##   <chr>    <chr>          <chr>                <chr>            <chr>           
## 1 grass7   GRASS          grass7:v.voronoi     v.voronoi        v.voronoi       
## 2 grass7   GRASS          grass7:v.voronoi.sk… v.voronoi.skele… v.voronoi.skele…
## 3 qgis     QGIS           qgis:voronoipolygons voronoipolygons  Voronoi polygons
qgis_show_help("qgis:voronoipolygons")
## Voronoi polygons (qgis:voronoipolygons)
## 
## ----------------
## Description
## ----------------
## This algorithm takes a points layer and generates a polygon layer containing the voronoi polygons corresponding to those input points.
## 
## 
## ----------------
## Arguments
## ----------------
## 
## INPUT: Input layer
##  Argument type:  source
##  Acceptable values:
##      - Path to a vector layer
## BUFFER: Buffer region (% of extent)
##  Argument type:  number
##  Acceptable values:
##      - A numeric value
## OUTPUT: Voronoi polygons
##  Argument type:  sink
##  Acceptable values:
##      - Path for new vector layer
## 
## ----------------
## Outputs
## ----------------
## 
## OUTPUT: <outputVector>
##  Voronoi polygons
groc_von<-qgis_run_algorithm(alg="qgis:voronoipolygons",
         INPUT=results.proj,
         OUTPUT=file.path(tempdir(), "grocvon.shp"),
         load_output = TRUE)

groc_von<-sf::read_sf(qgis_output(groc_von, "OUTPUT"))

mapview(groc_von, alpha=.75)+
  mapview(results.proj, col.regions="green")

Nearest Neighbor analysis

library(spatstat)
groc.pp<-as.ppp(as(results.proj, "Spatial"))

plot(nearest.neighbour(groc.pp))

algs[grepl(pattern = "nearest", x = algs$algorithm ),]
## # A tibble: 10 x 5
##    provider provider_title  algorithm       algorithm_id     algorithm_title    
##    <chr>    <chr>           <chr>           <chr>            <chr>              
##  1 gdal     GDAL            gdal:gridinver… gridinversedist… Grid (IDW with nea…
##  2 gdal     GDAL            gdal:gridneare… gridnearestneig… Grid (Nearest neig…
##  3 native   QGIS (native c… native:angleto… angletonearest   Align points to fe…
##  4 native   QGIS (native c… native:joinbyn… joinbynearest    Join attributes by…
##  5 native   QGIS (native c… native:nearest… nearestneighbou… Nearest neighbour …
##  6 qgis     QGIS            qgis:distancet… distancetoneare… Distance to neares…
##  7 qgis     QGIS            qgis:distancet… distancetoneare… Distance to neares…
##  8 qgis     QGIS            qgis:knearestc… knearestconcave… Concave hull (k-ne…
##  9 saga     SAGA            saga:knearestn… knearestneighbo… K-nearest neighbou…
## 10 saga     SAGA            saga:nearestne… nearestneighbour Nearest neighbour
qgis_show_help("native:nearestneighbouranalysis")
## Nearest neighbour analysis (native:nearestneighbouranalysis)
## 
## ----------------
## Description
## ----------------
## This algorithm performs nearest neighbor analysis for a point layer.
## 
## The output describes how the data are distributed (clustered, randomly or distributed).
## 
## Output is generated as an HTML file with the computed statistical values.
## 
## ----------------
## Arguments
## ----------------
## 
## INPUT: Input layer
##  Argument type:  source
##  Acceptable values:
##      - Path to a vector layer
## OUTPUT_HTML_FILE: Nearest neighbour
##  Argument type:  fileDestination
##  Acceptable values:
##      - Path for new file
## 
## ----------------
## Outputs
## ----------------
## 
## OUTPUT_HTML_FILE: <outputHtml>
##  Nearest neighbour
## OBSERVED_MD: <outputNumber>
##  Observed mean distance
## EXPECTED_MD: <outputNumber>
##  Expected mean distance
## NN_INDEX: <outputNumber>
##  Nearest neighbour index
## POINT_COUNT: <outputNumber>
##  Number of points
## Z_SCORE: <outputNumber>
##  Z-score
groc_nn<-qgis_run_algorithm(alg="native:nearestneighbouranalysis",
         INPUT=results.proj,
        OUTPUT_HTML_FILE=file.path(tempdir(), "grocnn.html"),
         load_output = TRUE)
## Ignoring unknown input 'load_output'
## Running /Applications/QGIS.app/Contents/MacOS/bin/qgis_process run \
##   'native:nearestneighbouranalysis' \
##   '--INPUT=/var/folders/_1/tkj8dh2n73s3c5fp80h0td380000gn/T//RtmpYVQfSd/filec1ea341d06a1/filec1ea2804cf5a.gpkg' \
##   '--OUTPUT_HTML_FILE=/var/folders/_1/tkj8dh2n73s3c5fp80h0td380000gn/T//RtmpYVQfSd/grocnn.html'
## 
## ----------------
## Inputs
## ----------------
## 
## INPUT:   /var/folders/_1/tkj8dh2n73s3c5fp80h0td380000gn/T//RtmpYVQfSd/filec1ea341d06a1/filec1ea2804cf5a.gpkg
## OUTPUT_HTML_FILE:    /var/folders/_1/tkj8dh2n73s3c5fp80h0td380000gn/T//RtmpYVQfSd/grocnn.html
## 
## 
## 0...10...20...30...40...50...60...70...80...90...100 - done.
## 
## ----------------
## Results
## ----------------
## 
## EXPECTED_MD: 4572.838994129232
## NN_INDEX:    0.5339201195487651
## OBSERVED_MD: 2441.530742422734
## OUTPUT_HTML_FILE:    /var/folders/_1/tkj8dh2n73s3c5fp80h0td380000gn/T//RtmpYVQfSd/grocnn.html
## POINT_COUNT: 349
## Z_SCORE: -16.657274867190246