如何从 R 中 Leaflet 地图上的多边形的空间多边形数据框制作动态标签

Question

使用此脚本，我将显示具有三个等时线的地图。我希望地图的标签包含每个 isochrone/polygon.

代表的最大时间

我应该如何在 addPolygons() 部分中引用空间数据框 (iso1/2/3)？

在下面的三个 addPolygons() 方法中，我尝试了不同的方法，但没有成功:(（尽管脚本仍然有效）。

library(osrm)
library(leaflet)
library(viridisLite)

# Making isochrones
iso1 = osrmIsochrone(loc = c(9.2,45.5), 
                    breaks = seq(from = 0,
                                 to = 45, 
                                 by = 5),
                    res=75)
iso2 = osrmIsochrone(loc = c(12.51182,41.92631), 
                     breaks = seq(from = 0,
                                  to = 45, 
                                  by = 15),
                     res=100)
iso3 = osrmIsochrone(loc = c(11.25581,43.76956), 
                     breaks = seq(from = 0,
                                  to = 45, 
                                  by = 15),
                     res=100)

# colors for leaflet 
vir = viridis(9)

# palette
pal1 <- colorNumeric(
  palette = vir,
  domain = iso1@data$id)
pal2 <- colorNumeric(
  palette = "Blues",
  domain = iso2@data$id)
pal3 <- colorNumeric(
  palette = "Reds",
  domain = iso3@data$id)

# Plotting interactive map using spdf
leaflet()%>%
  addTiles("http://mt0.google.com/vt/lyrs=m&hl=en&x={x}&y={y}&z={z}&s=Ga", attribution = 'Google')%>%
  addPolygons(data = iso1,
              fill = TRUE, 
              fillOpacity = 0.7,
              fillColor = ~pal1(id),stroke = FALSE, label = iso1@data$max)%>%
  addPolygons(data = iso2,
              fill = TRUE, 
              fillOpacity = 0.7,
              fillColor = ~pal2(id),stroke = FALSE, label = ~max)%>%
  addPolygons(data = iso3,
              fill = TRUE, 
              fillOpacity = 0.7,
              fillColor = ~pal3(id),stroke = FALSE, label = ~iso3@data$max)

Answer 1

leaflet()%>%
  addTiles("http://mt0.google.com/vt/lyrs=m&hl=en&x={x}&y={y}&z={z}&s=Ga", attribution = 'Google')%>%
  addPolygons(data = iso1,
              fill = TRUE, 
              group = "label1",
              fillOpacity = 0.7,
              fillColor = ~pal1(id),stroke = FALSE, label = iso1@data$max)%>%
  addPolygons(data = iso2,
              fill = TRUE, 
              group = "label2",
              fillOpacity = 0.7,
              fillColor = ~pal2(id),stroke = FALSE, label = ~max)%>%
  addPolygons(data = iso3,
              fill = TRUE, 
              group = "label3",
              fillOpacity = 0.7,
              fillColor = ~pal3(id),stroke = FALSE, label = ~iso3@data$max)

使用组参数指定标签。

Answer 2

如果您向标签提供最大值 as.character，它就会起作用。

library(osrm)
library(leaflet)
library(viridisLite)

# Making isochrones
iso1 = osrmIsochrone(loc = c(9.2,45.5), 
                     breaks = seq(from = 0,
                                  to = 45, 
                                  by = 5),
                     res=75)
iso2 = osrmIsochrone(loc = c(12.51182,41.92631), 
                     breaks = seq(from = 0,
                                  to = 45, 
                                  by = 15),
                     res=100)
iso3 = osrmIsochrone(loc = c(11.25581,43.76956), 
                     breaks = seq(from = 0,
                                  to = 45, 
                                  by = 15),
                     res=100)

# colors for leaflet 
vir = viridis(9)

# palette
pal1 <- colorNumeric(
  palette = vir,
  domain = iso1@data$id)
pal2 <- colorNumeric(
  palette = "Blues",
  domain = iso2@data$id)
pal3 <- colorNumeric(
  palette = "Reds",
  domain = iso3@data$id)

# Plotting interactive map using spdf
leaflet()%>%
  addTiles("http://mt0.google.com/vt/lyrs=m&hl=en&x={x}&y={y}&z={z}&s=Ga", attribution = 'Google')%>%
  addPolygons(data = iso1,
              fill = TRUE, 
              fillOpacity = 0.7,
              fillColor = ~pal1(id),stroke = FALSE, label = as.character(iso1@data$max))%>%
  addPolygons(data = iso2,
              fill = TRUE, 
              fillOpacity = 0.7,
              fillColor = ~pal2(id),stroke = FALSE, label = as.character(iso2@data$max))%>%
  addPolygons(data = iso3,
              fill = TRUE, 
              fillOpacity = 0.7,
              fillColor = ~pal3(id),stroke = FALSE, label = as.character(iso3@data$max))

如何从 R 中 Leaflet 地图上的多边形的空间多边形数据框制作动态标签

How to make dynamic labels from a spatial polygons dataframe for Polygons on a Leaflet map in R

r

geospatial

leaflet

osrm

r-leaflet