How to adjust the addPolylines function in shiny?

问题

Could you help me adjust the addPolylines on the second map ?? In the first it worked correctly, however in the second it did not show the red lines connecting one point to the other. I couldn't see what the error might be. I appreciate any help. I inserted an image below to illustrate.

library(shiny)
library(ggplot2)
library(rdist)
library(geosphere)
library(shinythemes)
library(leaflet)

function.cl<-function(df,k,Filter1,Filter2){
  
  #database df
  df<-structure(list(Properties = c(1,2,3,4,5,6,7), 
                     Latitude = c(-23.8, -23.8, -23.9, -23.9, -23.9,-23.4,-23.5), 
                     Longitude = c(-49.6, -49.3, -49.4, -49.8, -49.6,-49.4,-49.2), 
                     Waste = c(526, 350, 526, 469, 285, 433, 456)), class = "data.frame", row.names = c(NA, -7L))
  
  
  #clusters
  coordinates<-df[c("Latitude","Longitude")]
  d<-as.dist(distm(coordinates[,2:1]))
  fit.average<-hclust(d,method="average") 
  clusters<-cutree(fit.average, k) 
  nclusters<-matrix(table(clusters))  
  df$cluster <- clusters 
  
  #specific cluster and specific propertie
  df1<-df[c("Latitude","Longitude")]
  df1$cluster<-as.factor(clusters)
  df_spec_clust <- df1[df1$cluster == Filter1,]
  df_spec_prop<-df[df$Properties==Filter2,]
  
  #Table to join df and df1
  data_table <- Reduce(merge, list(df, df1))
  
  #Color and Icon for map
  ai_colors <-c("red","gray","blue","orange","green","beige","darkgreen","lightgreen", "lightred", "darkblue","lightblue",
                "purple","darkpurple","pink", "cadetblue","white","darkred", "lightgray","black")
  clust_colors <- ai_colors[df$cluster]
  icons <- awesomeIcons(
    icon = 'ios-close',
    iconColor = 'black',
    library = 'ion',
    markerColor =  clust_colors)
  
  leafIcons <- icons(
    iconUrl = ifelse(df1$Properties,
                     "https://image.flaticon.com/icons/svg/542/542461.svg"
    ),
    iconWidth = 45, iconHeight = 40,
    iconAnchorX = 25, iconAnchorY = 12)
  html_legend <- "<img src='https://image.flaticon.com/icons/svg/542/542461.svg'>"
  
  # Map for all clusters:
  m1<-leaflet(df1) %>% addTiles() %>%
    addMarkers(~Longitude, ~Latitude, icon = leafIcons) %>%
    addAwesomeMarkers(lat=~df$Latitude, lng = ~df$Longitude, icon=icons, label=~as.character(df$cluster)) %>% 
    addPolylines(lat=~df$Latitude, lng = ~df$Longitude,color="red") %>% 
    addLegend( position = "topright", title="Cluster", colors = ai_colors[1:max(df$cluster)],labels = unique(df$cluster))
    
  plot1<-m1
  
  # Map for specific cluster and propertie
  m2<-leaflet(df_spec_clust) %>% addTiles() %>%
    addMarkers(~Longitude, ~Latitude, icon = leafIcons) %>%
    addAwesomeMarkers(lat=~df_spec_prop$Latitude, lng = ~df_spec_prop$Longitude, icon=icons, label=~as.character(df$cluster))%>% 
    addPolylines(lat=~df_spec_prop$Latitude, lng = ~df_spec_prop$Longitude,color="red")
    plot2<-m2
  
  
  return(list(
    "Plot1" = plot1,
    "Plot2" = plot2,
    "Data" = data_table
  ))
}

ui <- bootstrapPage(
  navbarPage(theme = shinytheme("flatly"), collapsible = TRUE,
             "Cl", 
             tabPanel("Solution",
                      sidebarLayout(
                        sidebarPanel(
                          tags$b(h3("Choose the cluster number?")),
                          sliderInput("Slider", h5(""),
                                      min = 2, max = 5, value = 3),
                        ),
                        mainPanel(
                          tabsetPanel(      
                            tabPanel("Solution", (leafletOutput("Leaf1",width = "95%", height = "600")))))
                        
                      ))),
  tabPanel("",
           sidebarLayout(
             sidebarPanel(
               selectInput("Filter1", label = h4("Select just one cluster to show"),""),
               selectInput("Filter2",label=h4("Select the cluster property designated above"),""),
             ),
             mainPanel(
               tabsetPanel(
                 tabPanel("Map", (leafletOutput("Leaf2",width = "95%", height = "600")))))
           )))

server <- function(input, output, session) {
  
  Modelcl<-reactive({
    function.cl(df,input$Slider,input$Filter1,input$Filter2)
  })
  
  output$Leaf1 <- renderLeaflet({
    Modelcl()[[1]]
  })
  
  output$Leaf2 <- renderLeaflet({
    Modelcl()[[2]]
  })
  
  observeEvent(input$Slider, {
    abc <- req(Modelcl()$Data)
    updateSelectInput(session,'Filter1',
                      choices=sort(unique(abc$cluster)))
  }) 
  
  observeEvent(input$Filter1,{
    abc <- req(Modelcl()$Data) %>% filter(cluster == as.numeric(input$Filter1))
    updateSelectInput(session,'Filter2',
                      choices=sort(unique(abc$Properties)))
  }) 
  
  
}

shinyApp(ui = ui, server = server)

Image as an example (Markers connect only with AwesomeMarkers)

Thank you very much friends!

Conflict with color of map 2

# Map for specific cluster and propertie
  if(nrow(df_spec_clust)>0){
    clust_colors <- ai_colors[df_spec_clust$cluster]
    icons <- awesomeIcons(
      icon = 'ios-close',
      iconColor = 'black',
      library = 'ion',
      markerColor =  clust_colors)
    m2<-leaflet(df_spec_clust) %>% addTiles() %>%
      addAwesomeMarkers(lat=~Latitude, lng = ~Longitude, icon=icons, label=~cluster) 
    plot2<-m2} else plot2 <- NULL
  

   for(i in 1:nrow(df_spec_clust)){
     df_line <- rbind(df_spec_prop[,c("Latitude","Longitude")],
                       df_spec_clust[i,c("Latitude","Longitude")])
      m2 <- m2 %>%
        addPolylines(data = df_line, 
                     lat=~Latitude, 
                     lng = ~Longitude,
                     color="red")
    }
    plot2<-m2

Warning: Error in eval: object 'm2' not found**

回答1:

After building your map, you need to iterate over each pair of points to join with a line, for example with a for loop:

for(i in 1:nrow(df_spec_clust)){
    df_line <- rbind(df_spec_prop[,c("Latitude","Longitude")],
                     df_spec_clust[i,c("Latitude","Longitude")])
    m2 <- m2 %>%
      addPolylines(data = df_line, 
                   lat=~Latitude, 
                   lng = ~Longitude,
                   color="red")
}

来源：https://stackoverflow.com/questions/61758233/how-to-adjust-the-addpolylines-function-in-shiny