I am creating a shiny dashboard to visualize the spread of COOVID 19 across the states of Australia.
The following is my data frame (covid_cases) with the number of confirmed cases, deaths and recoveries
region Confirmed Deaths Recovered
<chr> <dbl> <dbl> <dbl>
1 Australian Capital Territory 113 3 110
2 New South Wales 4218 53 3118
3 Northern Territory 33 0 31
4 Queensland 1157 6 1141
5 South Australia 468 4 462
6 Tasmania 230 13 217
7 Victoria 20149 787 18901
8 Western Australia 676 9 651
In my server, I join the covid_cases data frame with the shapefile and color the states using the 'Cofirmed' cases. This works fine.
server <- function(input, output) {
output$ausmap <- renderLeaflet({
states_data <- read_sf("https://raw.githubusercontent.com/rowanhogan/australian-states/master/states.geojson") %>%
dplyr::left_join(covid_cases, by=c("STATE_NAME" = "region"))
pal <- colorQuantile("Blues", domain = states_data$Confirmed)
leaflet(states_data) %>%
addTiles() %>%
addPolygons(fillColor=~pal(Confirmed),
fillOpacity=0.8,
color="white", weight=1) %>%
fitBounds(110.246193, -50.322817, 155.226126, -9.088012)
})
}
However, I now want to color the states based on user input. And Have implemented the following radioGroupButtons in my UI component.
UI <- dashboradBody(
fluidRow(
radioGroupButtons(
inputId = "casetype",
label = NULL,
choices = c("Confirmed", "Deaths", "Recovered"),
selected = "Confirmed"
),
leafletOutput("ausmap")
)
)
and updated my server as follows
server <- function(input, output) {
output$ausmap <- renderLeaflet({
states_data <- read_sf("https://raw.githubusercontent.com/rowanhogan/australian-states/master/states.geojson") %>%
dplyr::left_join(covid_cases, by=c("STATE_NAME" = "region"))
pal <- colorQuantile("Blues", domain = states_data$Confirmed)
leaflet(states_data) %>%
addTiles() %>%
addPolygons(fillColor=~pal(input$casetype),
fillOpacity=0.8,
color="white", weight=1) %>%
fitBounds(110.246193, -50.322817, 155.226126, -9.088012)
})
}
This gives me an error stating "'x' must be numeric".
I would also like to change the color palette based on the input (ex: deaths - red, confirmed -blue, recovered - green). But am unsure how to update this.
I am not sure, if it's the best way (somehow it feels like this should be done with reactive values, but I am still trying to figure out the details of shiny ... especially the reactive details :D) ... anyways ... here is a solution that should work :)
The trick was to use helper variables for the casetype and pal. The error you got (numeric input) was, because pal needs the numeric data (deaths,...) to map the color and not the category (casetype)
output$ausmap <- leaflet::renderLeaflet({
url <- paste0("https://raw.githubusercontent.com/rowanhogan/",
"australian-states/master/states.geojson")
selected_col <- switch(input$casetype,
"Confirmed"="Blues",
"Deaths"="Reds",
"Recovered"="Greens")
states_data <- sf::read_sf(url) %>%
dplyr::left_join(covid_cases %>%
dplyr::select(region,selected=input$casetype),
by=c("STATE_NAME" = "region"))
pal <- leaflet::colorQuantile(selected_col, domain = states_data$selected)
leaflet::leaflet(states_data) %>%
leaflet::addTiles() %>%
leaflet::addPolygons(fillColor=~pal(selected),
fillOpacity=0.8,
color="white",
weight=1) %>%
leaflet::fitBounds(110.246193, -50.322817, 155.226126, -9.088012)
})