[英]How to access polygon information from shapefile leaflet R
我使用https://data.london.gov.uk/dataset/statistical-gis-boundary-files-london和閃亮的R和傳單制作了倫敦地圖。 我向shapefile添加了一個屬性,現在希望當用戶單擊特定多邊形時能夠突出顯示shapefile並打印信息。
我查看了閃亮的傳單ploygon click事件 , R傳單中的Marker鼠標單擊事件是否有光澤以及如何正確實現input $ map_marker_click? ,並且知道我需要使用ObserveEvent
,但無法正確實現它。
我的代碼是:
library(shiny)
library("rgdal")
library(leaflet)
shapeData <- readOGR('statistical-gis-boundaries-london/ESRI/LSOA_2004_London_Low_Resolution.shp')
shapeData <- spTransform(shapeData, CRS("+proj=longlat +ellps=GRS80"))
shapeData$col=sample(c('red','yellow','green'),nrow(shapeData),1) #add some value you want to map
borough=read.csv('BoroughCentres.csv')
ui=fluidPage(
fluidPage(
leafletOutput('LSOAMap'),
p(),
selectInput('LANAME','Borough',
choices = unique(shapeData$LA_NAME))
)
)
server=function(input, output) {
output$LSOAMap <- renderLeaflet({
llong=borough[borough$Borough==input$LANAME,3]
llat=borough[borough$Borough==input$LANAME,4]
bor=subset(shapeData,shapeData$LA_NAME %in% input$LANAME)
leaflet() %>% addTiles() %>%
setView(lng = llong, lat=llat,zoom=13) %>%
addPolygons(data=bor,weight=2,col = 'black',fillOpacity = 0.2,fillColor = bor$col,
highlightOptions = highlightOptions(color='white',weight=1,
bringToFront = TRUE)) %>%
addMarkers(lng = llong,lat=llat,popup=input$LANAME)
})
}
shinyApp(ui, server)
我嘗試添加以及session
作為參數:
observe({
click <- input$map_marker_click
if (is.null(click))
return()
print(click)
text <-
paste("Lattitude ",
click$lat,
"Longtitude ",
click$lng)
leafletProxy(mapId = "LSOAMap") %>%
clearPopups() %>%
addPopups(dat = click, lat = ~lat, lng = ~lng, popup = text)
# map$clearPopups()
# map$showPopup(click$latitude, click$longtitude, text)
})
無濟於事。
我想要的是,當用戶突出顯示特定形狀時,文本會彈出並顯示shapefile中對應的STWARDNAME
。
自治市鎮的前幾行是:
> head(borough)
Borough LA_CODE long lat
1 City of London E09000001 -0.09194991 51.51814
2 Barking and Dagenham E09000002 0.13064556 51.54764
3 Barnet E09000003 -0.20416711 51.61086
4 Bexley E09000004 0.13459320 51.45981
5 Brent E09000005 -0.26187070 51.55697
6 Bromley E09000006 0.03734663 51.38836
您非常接近,但是有一些語法問題,我認為這使您感到困惑。
首先,您沒有從SPDF中正確選擇想要的STWARDNAME
,因此R無法知道要顯示哪個STWARDNAME
。 我加了這條線
popup = subset(shapeData, LA_NAME == input$LANAME )$STWARDNAME
另外,您應該將highlightOptions
作為選項傳遞時才應highlight
最后,由於您對多邊形的鼠標懸停更加感興趣,因此我刪除了彈出標記,並更改為highlight
以便在將鼠標懸停在多邊形上時highlight
名稱:
leaflet() %>% addTiles() %>%
setView(lng = llong, lat=llat,zoom=13) %>%
addPolygons(data=bor,weight=2,col = 'black',fillOpacity = 0.2,fillColor = bor$col,
highlight = highlightOptions(color='white',weight=1,
bringToFront = TRUE), label= popup)
@Stedy的回答很棒,而且更好,我只是采用了另一種方式。 我添加了一個圖層ID向量,並彈出了查找STWARDNAME的決定
lid=as.vector(row.names(bor@data))
pu=bor@data[row.names(bor@data)==lid,'STWARDNAME']
,然后在使地圖layerId = lid,popup = pu,
同時添加了兩個參數。 用戶單擊區域時顯示的彈出窗口
bor=subset(shapeData,shapeData$LA_NAME %in% input$LANAME)
lid=as.vector(row.names(bor@data))
pu=bor@data[row.names(bor@data)==lid,'STWARDNAME']
leaflet() %>% addTiles() %>%
setView(lng = llong, lat=llat,zoom=13) %>%
addPolygons(data=bor,weight=2,col = 'black',fillOpacity = 0.2,fillColor = bor$col,
layerId = lid,popup = pu,
highlightOptions = highlightOptions(color='white',weight=1,
bringToFront = TRUE)) %>%
addMarkers(lng = llong,lat=llat,popup=input$LANAME)
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