How to create shiny app using stacked raster image?

[prasenjit.ac]

I want to create a shiny app using a stacked raster image. I have successfully created it in r-studio. However, I am getting no response from shiny while I run the app. A reproducible code is attached here for r studio and shiny.

#generate raster layers
rst1 = matrix(runif(400, 0, 1),20, 20)# for suitability layer
rst2 = matrix(rnorm(400, 800, 50), 20, 20)# for precipitation
rst3 = matrix(rnorm(400, 27, 2.5), 20, 20)# for mean temperature
rst4 = matrix(rnorm(400, 38, 1.5), 20, 20)# for max. temperature
rst5 = matrix(rnorm(400, 21, 0.5), 20, 20)# for min. temperature

suit1 = raster(rst1)
precip1 = raster(rst2)
mean.T = raster(rst3)
max.T = raster(rst4)
min.T = raster(rst5)

# stack the raster layers
s1 = stack(suit1, precip1, mean.T, max.T, min.T)

# create extent and assign projection
extent(s1) = c(68,82,23,38)
projection(s1) <- CRS("+proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0")

f2 <- function(x){
  x1 = x[1]
  x2 = x[2]
  x3 = x[3]
  x4 = x[4]
  x5 = x[5]
  ifelse(is.na(x1)== T, NA, ifelse(x2 >= 700 & x2 <= 880 & x3 <= 28 &
                                     x4 <= 40 & x5 <= 22, x1, NA))
}
s_new = overlay(s1, fun = f2)


The shiny app code:

ui <- fluidPage(
  tags$style(type = "text/css", "html, body {width:100%;height:100%}"),
  titlePanel('Cactus Suitability'),
  #leafletOutput("map", width = "100%", height = "100%"),
  sidebarLayout(
    sidebarPanel(sliderInput('l2', 'Precip', min = 640
                             ,max = 950 
                             ,value = c(700,800)
                             ,step = 25),
                 sliderInput('l3', 'Mean Temperature (C)', min = 20
                             ,max = 34
                             ,value = c(20,25), step = 1),
                 sliderInput('l4', 'Max Temperature (C)', min = 32
                             ,max = 43
                             ,value = c(35,40), step = 1),
                 sliderInput('l5', 'Min Temperature (C)', min = 19
                             ,max = 23
                             ,value = c(19, 20), step = 0.5)),
                 
    mainPanel(leafletOutput("map", width = "100%", height = "100%"))
  )
  
)

#shiny server
server <- function(input, output, session){
  filteredData <- reactive({
    calc(s1, fun = function(x){
      x1 = x[1]
      x2 = x[2]
      x3 = x[3]
      x4 = x[4]
      x5 = x[5]
      ifelse(is.na(x1)== T, NA, ifelse(x2 > input$l2[1] & x2 < input$l2[2] 
                                       & x3 > input$l3[1] & x3 < input$l3[2] 
                                       & x4 > input$l4[1] & x4 < input$l4[2]
                                       & x5 > input$l5[1] & x5 < input$l5[2],
                                       x1, NA))
    })
  })
  
  pal <- colorNumeric("RdYlBu", values(s1[[1]]), 
                      na.color = "transparent")
  output$map <- renderLeaflet({
    leaflet() %>% addProviderTiles('Esri.WorldImagery') %>%
      addRasterImage(filteredData(), colors = pal, opacity = 1) %>%
      addLegend(position = "bottomright", pal = pal, values = values(s1[[1]]),
                opacity = 1)
  })
}

shinyApp(ui, server)

[FJCC]

I do not know why, but changing your mainPanel() call to the following seems to work. At least an image is produced and it responds to changes in the slider settings.

mainPanel(leafletOutput("map", width = "100%"))

[prasenjit.ac]

Thanks for the reply. I still can't figured out the reason for that. But now, at least I get an image which I need.
regards.