Building Quadrants in Rshiny - r

Question

I wanna build quadrants on my leaflet as part of my quadrat analysis. currently I have my tessalation object and im trying to draw the tiles on my leaflet. My code is below
library(spatstat)
library(leaflet)
firms_ppp <- ppp(x=cbd_points#coords[,1],y=cbd_points#coords[,2], window =
window)
qc <- quadratcount(firms_ppp)
qc.nu <- as.numeric(qc)
qc.tess <- as.tess(qc)
colorpal4 <- colorNumeric("red",c(min(qc.nu, na.rm = TRUE),max(qc.nu, na.rm = TRUE)))
for (j in 1:length(qc.tess$window$yrange)) {
for (i in 1:length(qc.tess$window$xrange[i])) {
leaflet() %>%
addRectangles(lng1 = qc.tess$window$xrange[i], lng2 = qc.tess$window$xrange[i+1],
lat1 = rev(qc.tess$window$yrange)[j], lat2 = rev(qc.tess$window$yrange)[j+1],
color = colorpal4(qc.nu[j+(i-1)*(length(qc.tess$window$yrange)-1)]),
popup = paste("<h3>",qc.nu[j+(i-1)*(length(qc.tess$window$yrange)-1)],"</h3>")
)
}
}
Any idea how I can build the quadrants? I tried with tiles as well but I cant seem to get it to work too! Pls Help!!

Answer 1

With 2 helping functions found here, which convert a Tesselation object into SpatialPolygons, you can achieve something like this:
library(spatstat)
library(leaflet)
library(sp)
## FUNCTIONS #####################
owin2Polygons <- function(x, id="1") {
stopifnot(is.owin(x))
x <- as.polygonal(x)
closering <- function(df) { df[c(seq(nrow(df)), 1), ] }
pieces <- lapply(x$bdry,
function(p) {
Polygon(coords=closering(cbind(p$x,p$y)),
hole=spatstat.utils::is.hole.xypolygon(p)) })
z <- Polygons(pieces, id)
return(z)
}
tess2SP <- function(x) {
stopifnot(is.tess(x))
y <- tiles(x)
nom <- names(y)
z <- list()
for(i in seq(y))
z[[i]] <- owin2Polygons(y[[i]], nom[i])
return(SpatialPolygons(z))
}
## DATA #####################
cbd_points <- data.frame(
long = runif(100,15,19),
lat = runif(100,40,50)
)
window <- owin(c(0,20), c(30,50))
firms_ppp <- ppp(x=cbd_points$long, y=cbd_points$lat, window = window)
qc <- quadratcount(firms_ppp)
qc.nu <- as.numeric(qc)
qc.tess <- as.tess(qc)
colorpal4 <- colorNumeric("red",c(min(qc.nu, na.rm = TRUE),max(qc.nu, na.rm = TRUE)))
PolyGrid <- tess2SP(qc.tess)
PolyGridDF <- SpatialPolygonsDataFrame(PolyGrid, data = data.frame(ID = 1:length(PolyGrid)), match.ID = F)
## SHINY ########################
library(shiny)
ui <- fluidPage(
leafletOutput("map")
)
server <- function(input, output, session) {
output$map <- renderLeaflet({
pal = colorFactor("viridis", as.character(PolyGridDF$ID))
leaflet() %>%
addTiles() %>%
addPolygons(data=PolyGridDF,
label = as.character(PolyGridDF$ID),
color = ~pal(as.character(PolyGridDF$ID)))
})
}
shinyApp(ui, server)