radius of circles in leaflet app to be driven by the selectInput - r

Question

I am trying to make the radius of my circle markers in this Shiny leaflet app be driven by the selectInput variable.
The dropdown has three values, "Week.1", "Week.2" and "Week.3", which are all numeric vectors (of large dollar revenue values in millions) in the d at the bottom of this question.
selectInput("weekView", "Week's Revenue:",
c("1" = "Week.1",
"2" = "Week.2",
"3" = "Week.3")),
I am currently loading Week.1 and get thr result. I wNt the input to change the weeks and react with the corresponding $ on the map.
When I try and use input$weekView instead of the static ~(Week.1), I get errors as it is "Week.1". I've tried using quote = False in place to remove them before the radius is calculated but I'm failing to find the right place to do so...
leaflet(data = P) %>%
addTiles() %>% # Add default OpenStreetMap map tiles
addCircleMarkers(~Long, ~Lat, popup = ~Week.1,
radius = ~(Week.1)/40000,
stroke = FALSE,
fillOpacity = 0.5)
Can any one advise on how best to go about this? What I want to say is
radius = input$weekView/40000
All the script:
library(shiny)
library(leaflet)
ui <- fluidPage(
selectInput("weekView", "Week's Revenue:",
c("1" = "Week.1",
"2" = "Week.2",
"3" = "Week.3")),
leafletOutput("mymap"),
p()
)
server <- function(input, output, session) {
output$mymap <- renderLeaflet({
x <- input$weekView
P<- read.csv("Lebara_weeks_rev4.csv")
as.numeric(P$Long)
as.numeric(P$Lat)
as.character(P$Week.1)
P$Week.1 <- as.numeric(gsub(",","",P$Week.1))
P$Week.2 <- as.numeric(gsub(",","",P$Week.2))
P$Week.3 <- as.numeric(gsub(",","",P$Week.3))
long <- P$Long
Lat <- P$Lat
leaflet(data = P) %>%
addTiles() %>% # Add default OpenStreetMap map tiles
addCircleMarkers(~Long, ~Lat, popup = ~Week.1,
radius = ~(Week.1)/40000,
stroke = FALSE,
fillOpacity = 0.5)
})
}
shinyApp(ui, server)
Head of the df = P
> head(P)
group Lat Long Country Week.1 Week.2 Week.3 Week.4
1 178.100 55.37805 -3.435973 United Kingdom 649,613 665,147 640,732 649,642
2 174.890 51.16569 10.451526 Germany 117,766 120,402 104,167 91,157
3 144.100 46.22764 2.213749 France 135,784 117,759 109,337 101,873
4 174.211 52.13263 5.291266 Netherlands 403,950 397,438 377,855 389,345
5 174.990 40.46367 -3.749220 Spain 94,472 95,742 88,313 86,400
6 178.600 56.26392 9.501785 Denmark 70,094 72,487 67,597 66,769
Thanks!
Pete
I used tidyr and subsetWeek1 <- P[1:7,] then made variables for the subsetWeek1$value/40000 to make them small enough for the radius values) of those subsets. I tried to make the selectInput 1 = subsetWeek1$value, 2 = subsetWeek2$value and 3 = subsetWeek3$value...
library(tidyr)
P <- tidyr::gather(P, week, value, Week.1:Week.3)
subsetWeek1 <- P[1:7,]
subsetWeek2 <- P[8:14,]
subsetWeek3 <- P[15:21,]
Week1val <- subsetWeek1$value
Week2val <- subsetWeek2$value
Week3val <- subsetWeek3$value
This doesn't seem to pick up the selectInput value and change the map. There are no markers on the map and no errors provided. Could it be the scale of the circles makes them invisible? In the non-app version they are OK.

Answer 1

You're close, you just need to update variable names and clean up a bit. Generally, if you're repeating the same line with a slightly different parameter, there's a better way. An option, using tidyr for gather and extract_numeric:
library(shiny)
library(tidyr)
library(leaflet)
P <- read.csv("Lebara_weeks_rev4.csv")
# do munging that won't change based on input here
P2 <- gather(P, week, value, Week.1:Week.4) # gather to long form
P2$value <- extract_numeric(P2$value) # convert to numeric
ui <- fluidPage(
selectInput("weekView", "Week's Revenue:",
c("1" = "Week.1",
"2" = "Week.2",
"3" = "Week.3",
"4" = "Week.4")),
leafletOutput("mymap")
)
server <- function(input, output, session) {
output$mymap <- renderLeaflet({
# do munging dependent on input here
P3 <- P2[P2$week == input$weekView, ] # subset based on input
leaflet(data = P3) %>%
addTiles() %>% # Add default OpenStreetMap map tiles
addCircleMarkers(lng = ~Long, lat = ~Lat,
popup = ~format(value, big.mark = ','), # reinsert commas
radius = ~value/40000,
stroke = FALSE,
fillOpacity = 0.5)
})
}
shinyApp(ui, server)