1

I am a new R Shiny user and I'm trying to map out all the destinations one can fly to from an origin airport.

I've successfully created a map that displays all the airports of a country when I hard code the country into my code (I've used Italy as an example).

What I want to be able to do is have a "selectinput" that allows a user to select a country and all of the corresponding airports will show up on the map.

Here is my code:

#----------Loading my data----------#
#Dataset 1: Routes
routes=read.csv(url("https://raw.githubusercontent.com/jpatokal/openflights/master/data/routes.dat"))


#Dataset #2: Airports
airports=read.csv(url("https://raw.githubusercontent.com/jpatokal/openflights/master/data/airports-extended.dat"))


#Give Better Names to Columns

colnames(routes)=c("Airline","AirlineID","IATA","SourceAP_ID","DestinationAirport","DestAP_ID","Codeshare","Stops","Equipment")

colnames(airports)=c("AirportID","Name","City","Country","IATA","ICAO","Latitude","Longitude","Altitude","Timezone","DST","TzDatabaseTz","Type","Source")

#Join datasets on Source Airport

fullair=merge(x=routes,y=airports,by="IATA",all.x=TRUE)


#----------Preprocessing Data---------#
fullair2=subset(fullair,fullair$Type=="airport")

fullair2$UniqueID=paste0(fullair2$IATA,"_",fullair2$DestinationAirport)

library(dplyr)
  group_by(IATA) %>%
  mutate(Count=n_distinct(UniqueID)) %>%
  ungroup()
fullair3=as.data.frame(fullair3)


fullair3=fullair3[!duplicated(fullair3[c("UniqueID")]),]

library(rowr)
library(sqldf)
library(RSQLite)



library(stringi)
fullair3$Region=stri_extract(fullair3$TzDatabaseTz, regex='[^/]*')

SpitOutNum=sqldf("select IATA,count(*)
                      from fullair3
                      group by IATA")
SpitOutNum=as.data.frame(SpitOutNum3)
colnames(SpitOutNum)=c("IATA","DestinationCount")
fullair3=merge(x=fullair3,y=SpitOutNum,by="IATA",all.x=TRUE)

#Create the full name
fullair3$NamePart1=paste("(",fullair3$IATA,")",sep ="")
fullair3$FullName=paste(fullair3$Name, fullair3$NamePart1)
fullair3$NamePart1=NULL


#Make destination specific columns like long and lat
SpitOutNum2=sqldf("select IATA, City, Country, Region, Name, DestinationCount, Longitude, 
Latitude
               from fullair3
               group by IATA,City, Country, Region, Name")
colnames(SpitOutNum2)=c("DestinationAirport","DestCity","DestCountry","DestRegion","DestAirportName","DestCount","DestLong","DestLat")
fullair3=merge(x=fullair3,y=SpitOutNum2,by="DestinationAirport",all.x=TRUE)


 #--------------------R Shiny App-------------------#


library(shinydashboard)
library(shiny)
library(leaflet)
library(leaflet.extras)
library(rgdal)
library(sp)
library(raster)

airportchoices=unique(fullair3$FullName)
countrychoices=unique(fullair3$Country)
regionchoices=unique(fullair3$Region)
Italy=subset(fullair3,fullair3$Country=="Italy")


# Define UI for application
ui <- fluidPage(
  dashboardPage(
    dashboardHeader(title="Airport Data"),
dashboardSidebar(
  sidebarMenu(
    menuItem(
      "Maps",
      tabName = "maps",
      icon=icon("globe")
    )
  )
),
dashboardBody(
  tabItems(
    tabItem(
      tabName = "maps",
      tags$style(type="text/css","#all_airports {height:calc(100vh - 80px) !important;}"),
      leafletOutput("all_airports"),
      selectInput(inputId = "countryselect",label="Select a country:",choices=countrychoices)

    )
  )
)
  )
)

 # Define server logic 
server <- function(input, output) {


  AirportData=reactive({
    filteredData=subset(fullair3,Country == input$countryselect)
    return(filteredData)
  })


  output$all_airports=renderLeaflet({

    data=AirportData()

    pal=colorNumeric("Reds",Italy$DestinationCount)


    leaflet(data=Italy) %>% 
      addTiles(group="OpenStreetMap")  %>%


         addCircles(radius = ~Italy$DestinationCount*250, 
             weight = 1, 
             color = "black", 
             fillColor = ~pal(Italy$DestinationCount),
             fillOpacity = 0.7,
             popup = paste0("Airport Name: ", Italy$Name, "<br>",
                            "City: ", Italy$City, "<br>",
                            "Destination Count: ",Italy$DestinationCount,"<br>"
                            ),
             label = ~as.character(Italy$IATA),
             group = "Points") #%>%



      #addMarkers(lng = ~Longitude,lat = ~Latitude, 
       #           popup=~as.character(DestinationCount), 
       #          label=~as.character(DestinationCount), 
       #          group = "Markers")
  })

}

# Run the application 
shinyApp(ui = ui, server = server)

This is my issue:

I'm not sure how to get the selectInput drop down menu to show up on my map and then connect its selection to the map.

How would I change the code above to do that?

Any help would be appreciated!

Improve this question

1 Answer 1

Reset to default
1

You have already done all the necessary work. Just replace all the hard coded Italy to data, which will have the subset of the airport data with the country that the user selects. I'd also consider moving the selectInput to the top of the dashboard as it's hard to scroll from the bottom and users might not see it. I've placed it top center to avoid the dropdown options being covered by the zoom in controls.

Updated code:

#----------Loading my data----------#
#Dataset 1: Routes
routes=read.csv(url("https://raw.githubusercontent.com/jpatokal/openflights/master/data/routes.dat"))


#Dataset #2: Airports
airports=read.csv(url("https://raw.githubusercontent.com/jpatokal/openflights/master/data/airports-extended.dat"))


#Give Better Names to Columns

colnames(routes)=c("Airline","AirlineID","IATA","SourceAP_ID","DestinationAirport","DestAP_ID","Codeshare","Stops","Equipment")

colnames(airports)=c("AirportID","Name","City","Country","IATA","ICAO","Latitude","Longitude","Altitude","Timezone","DST","TzDatabaseTz","Type","Source")

#Join datasets on Source Airport

fullair=merge(x=routes,y=airports,by="IATA",all.x=TRUE)


#----------Preprocessing Data---------#
fullair2=subset(fullair,fullair$Type=="airport")

fullair2$UniqueID=paste0(fullair2$IATA,"_",fullair2$DestinationAirport)

library(dplyr)

fullair3 = fullair2 %>%
  group_by(IATA) %>%
  mutate(Count=n_distinct(UniqueID)) %>%
  ungroup()

fullair3=as.data.frame(fullair3)


fullair3=fullair3[!duplicated(fullair3[c("UniqueID")]),]

library(rowr)
library(sqldf)
library(RSQLite)



library(stringi)
fullair3$Region=stri_extract(fullair3$TzDatabaseTz, regex='[^/]*')

SpitOutNum=sqldf("select IATA,count(*)
                      from fullair3
                      group by IATA")

# SpitOutNum=as.data.frame(SpitOutNum3)

colnames(SpitOutNum)=c("IATA","DestinationCount")
fullair3=merge(x=fullair3,y=SpitOutNum,by="IATA",all.x=TRUE)

#Create the full name
fullair3$NamePart1=paste("(",fullair3$IATA,")",sep ="")
fullair3$FullName=paste(fullair3$Name, fullair3$NamePart1)
fullair3$NamePart1=NULL


#Make destination specific columns like long and lat
SpitOutNum2=sqldf("select IATA, City, Country, Region, Name, DestinationCount, Longitude, 
Latitude
               from fullair3
               group by IATA,City, Country, Region, Name")
colnames(SpitOutNum2)=c("DestinationAirport","DestCity","DestCountry","DestRegion","DestAirportName","DestCount","DestLong","DestLat")
fullair3=merge(x=fullair3,y=SpitOutNum2,by="DestinationAirport",all.x=TRUE)


#--------------------R Shiny App-------------------#


library(shinydashboard)
library(shiny)
library(leaflet)
library(leaflet.extras)
library(rgdal)
library(sp)
library(raster)

airportchoices=unique(fullair3$FullName)
countrychoices=unique(fullair3$Country)
regionchoices=unique(fullair3$Region)
Italy=subset(fullair3,fullair3$Country=="Italy")

countrychoices <- as.character(countrychoices)
countrychoices <- sort(countrychoices)

# Define UI for application
ui <- fluidPage(
  dashboardPage(
    dashboardHeader(title="Airport Data"),
    dashboardSidebar(
      sidebarMenu(
        menuItem(
          "Maps",
          tabName = "maps",
          icon=icon("globe")
        )
      )
    ),
    dashboardBody(
      tabItems(
        tabItem(
          tabName = "maps",
          tags$style(type="text/css","#all_airports {height:calc(100vh - 80px) !important;}"),

          fluidRow(column(4),
                   column(8,
                          selectInput(inputId = "countryselect",label="Select a country:",choices=countrychoices, selected = "France")
                          )),

          leafletOutput("all_airports")

        )
      )
    )
  )
)

# Define server logic 
server <- function(input, output) {


  AirportData=reactive({
    filteredData=subset(fullair3,Country == input$countryselect)
    return(filteredData)
  })


  output$all_airports=renderLeaflet({

    data=AirportData()

    pal=colorNumeric("Reds",data$DestinationCount)


    leaflet(data=data) %>% 
      addTiles(group="OpenStreetMap")  %>%


      addCircles(radius = ~data$DestinationCount*250, 
                 weight = 1, 
                 color = "black", 
                 fillColor = ~pal(data$DestinationCount),
                 fillOpacity = 0.7,
                 popup = paste0("Airport Name: ", data$Name, "<br>",
                                "City: ", data$City, "<br>",
                                "Destination Count: ",data$DestinationCount,"<br>"
                 ),
                 label = ~as.character(data$IATA),
                 group = "Points") #%>%



    #addMarkers(lng = ~Longitude,lat = ~Latitude, 
    #           popup=~as.character(DestinationCount), 
    #          label=~as.character(DestinationCount), 
    #          group = "Markers")
  })

}

# Run the application 
shinyApp(ui = ui, server = server)

enter image description here

Improve this answer
4
  • Thank you sir! I tried replacing the country name with data and it wasn't working for me --> guess I had the selectInput in the wrong place. Thanks for helping me through the finish line!
    – user2813606
    Commented Apr 19, 2020 at 18:54
  • Did you copy my code? The answer I've posted has already done that for you
    – Mr.Rlover
    Commented Apr 19, 2020 at 19:00
  • Sorry - I should have clarified --> before posting I tried switching Italy with data and it didn't work, but I'm assuming since the only other thing I have changed was the placement of the selectInput statement that that was the issue for me.
    – user2813606
    Commented Apr 20, 2020 at 1:08
  • The circles are not showing if I run this code in RStudio.
    – Zizzipupp
    Commented Nov 17, 2021 at 16:21

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