In-class_Ex05

1 Install and load packages

pacman::p_load(tidyverse, sf, sfdep, tmap)

2

studyArea <- st_read(dsn = "data", layer = "study_area") %>%
  st_transform(3829)

Reading layer `study_area' from data source 
  `C:\kt-x\is415-GAA\In-class_Ex\In-class_Ex05\data' using driver `ESRI Shapefile'
Simple feature collection with 7 features and 7 fields
Geometry type: POLYGON
Dimension:     XY
Bounding box:  xmin: 121.4836 ymin: 25.00776 xmax: 121.592 ymax: 25.09288
Geodetic CRS:  TWD97

stores <- st_read(dsn = "data", layer = "stores") %>%
  st_transform(3829)

Reading layer `stores' from data source 
  `C:\kt-x\is415-GAA\In-class_Ex\In-class_Ex05\data' using driver `ESRI Shapefile'
Simple feature collection with 1409 features and 4 fields
Geometry type: POINT
Dimension:     XY
Bounding box:  xmin: 121.4902 ymin: 25.01257 xmax: 121.5874 ymax: 25.08557
Geodetic CRS:  TWD97

tmap_mode("view")
tm_shape(studyArea) + 
  tm_polygons() + 
tm_shape(stores) + 
  tm_dots(col = "Name", 
          size = 0.01, 
          border.col = "black", 
          border.lwd = 0.5) + 
  tm_view(set.zoom.limits = c(12, 16))

3 Local Colocation Quotients (LCLQ)

nb <- include_self(
  st_knn(st_geometry(stores), 6)
)

wt <- st_kernel_weights(nb, 
                        stores, 
                        "gaussian",
                        adaptive = TRUE)

FamilyMart <- stores %>%
  filter(Name == "Family Mart")
A <- FamilyMart$Name
SevenEleven <- stores %>%
  filter(Name == "7-Eleven")
B<- SevenEleven$Name

LCLQ <- local_colocation(A, B, nb, wt, 49)

LCLQ_stores <- cbind(stores, LCLQ)
#cannot do left-join/right-join cause no unique identifier
tmap_mode("view")