Week 4 Assignment - Generate Random Landmarks

This app places landmarks randomly on a map using leaflet

• Provide the 4 inputs
  • Latitude
  • Longitude
  • Range
  • Number of Landmarks
• Click the generate map button
• Should generate a map with the number of landmarks specified and placed randomly between the latitude and langitude values specified by the range.
• The default values are for the city of New York.

I have omitted the documentation lines since the code is too large to fit in one slide.

library(shiny)
library(dplyr)
library(leaflet)
ui <- fluidPage(
    headerPanel("Create Random Landmarks"),
    headerPanel(" "),# Add vertical space between two lines
    sidebarPanel(# Documentation lines
                 numericInput("lat", "Latitude", value = 40.7128, min = -90.0000, max = 90.0000 ),
                 # Documentation lines
                 numericInput("lon", "Longitude", value = -74.0060, min = -180.0000, max = 180.0000 ),
                 # Documentation lines
                 sliderInput("rnge", "Range", value = 0.05, min = 0.00, max = 1.00),
                 # Documentation lines
                 numericInput("no_of_points", "Number of Landmarks", value = 500, min = 100, max = 1500),
                 actionButton("submit", "Generate Map"),
                 width = 3),
    mainPanel(leafletOutput("map")))

Generates and displays the markers on the leaflet map

server <- function(input, output, session) {


    df <- eventReactive(input$submit, { data.frame(lat = runif(input$no_of_points,
                                 min = input$lat - input$rnge,
                                 max = input$lat + input$rnge),
                     lng = runif(input$no_of_points,
                                 min = input$lon - input$rnge,
                                 max = input$lon + input$rnge))
    })

    output$map <- renderLeaflet(leaflet(data = df()) %>%
                                    addTiles() %>%
                                    addMarkers(clusterOptions = markerClusterOptions()))
}

• Link to the app:

https://shouankshastri.shinyapps.io/Week_4_Assignment/

• Link to the repo:

https://github.com/shounakshastri/Developing-Data-Products-Assignment