Question

BLschool.csv文件。我想要做的是根据所选的选项更改地图。

因此，如果选择A，则地图应仅显示质量等级为A的学校，同样适用于B，C，{{1 }}

但是，在D值没有进入的某个地方，或者由于某种原因数据不是子集，我收到此错误：

input$schoolqual

server.R

Error: schqual not found

ui.R

sc <- read.csv("BLschools.csv", header = TRUE, sep=",")

shinyServer(function(input, output){


  output$map <- renderLeaflet({

  schqual <- input$schoolqual %>%
  school <- subset(sc, sc$Rateoutof4 == schqual) %>%
  leaflet(data = school) %>%
  setView(lng = -73.98928, lat = 40.75042, zoom = 10) %>%
  addProviderTiles("CartoDB.Positron", options = providerTileOptions(noWrap = TRUE)) %>%
  addMarkers(clusterOptions = markerClusterOptions(~lng, ~lat), icon = greenLeafIcon, 
             popup= ~paste("<b>", as.character(school$SchoolName),"</b><br/>",
             "Rating: ", as.character(school$Rateoutof4),"<p></p>"))
  })

})

请忽略shinyUI( fluidPage( titlePanel("NYC schools"), sidebarLayout( sidebarPanel( selectInput(schoolqual, choices = c("A", "B","C", "D", "E"), selected = "A", label="school quality rating")), mainPanel(leafletOutput("map")) ) ) )的事实，尽管名称是字符。我忘了更改列名。

Answer 1

您可以尝试使用反应式表达式：

shinyServer(function(input, output){
  school <- reactive(subset(sc, sc$Rateoutof4 == input$schoolqual))
  output$map <- renderLeaflet({
    leaflet(data = school()) %>%
    setView(lng = -73.98928, lat = 40.75042, zoom = 10) %>%
    addProviderTiles("CartoDB.Positron", 
                     options = providerTileOptions(noWrap = TRUE)) %>%
    addMarkers(clusterOptions = markerClusterOptions(~lng, ~lat), 
               icon = greenLeafIcon, 
               popup= ~paste("<b>", 
                             as.character(school()$SchoolName),
                             "</b><br/>",
                             "Rating: ", 
                             as.character(school()$Rateoutof4),
                             "<p></p>"))
  })
})

R - Shiny widget和Leaflet没有连接

1 个答案: