In-class Exercise 5: Local Co-Location Quotient in

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

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

Reading layer `study_area' from data source 
  `C:\tiffanik\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(crs = 3829)

Reading layer `stores' from data source 
  `C:\tiffanik\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

Visualising the sf layers

tmap_mode ("view")

tmap mode set to interactive viewing

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))

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)