R Shiny not responding inputs

Question

I am trying to learn R Shiny in Rstudio. I have used the code below to define the use interface.

# Vamos a simular modelos poisson compuestos con diferentes

# distribuciones de severidad.

library(actuar)

library(shiny)

# Define UI for application that draws a histogram

ui <- fluidPage(

    # Número de simulaciones

    headerPanel('Número de simulaciones'),

    numericInput(inputId = "n",label = NULL,

                 value = 10,min = 1,max = 20000),

    # Gráfica S exponencial.

    headerPanel('Exponencial'),

    sidebarPanel(

    sliderInput(inputId = 'lambda1',label = 'Lambda 1',value = 7,

                min = 0, max = 15),

    sliderInput(inputId = 'rate',label = 'rate',value = 5,

                    min = 0, max = 15),

    ),

    mainPanel(

        plotOutput('plot1')

    )

)

# Define server logic required to draw a histogram

server <- function(input, output) {

    output$plot1 <- renderPlot({

        #Preparativos para los gráficos:

        set.seed(20)

        n <- input$n

        lambda1 <- input$lambda1

        rate <- input$rate

        S1 <- rcompound(n = n, #Genera n

                        model.freq = rpois(lambda1), #N~Poi(lambda1)

                        model.sev = rexp(rate = 2)) #Y~Exp(rate)

        MASS::truehist(S1,

                       col=rainbow(125, start = 0.5, 1),

                       main = "exp",nbins = 125)

        abline(h=0,v=0,col="black",lwd=2)

    })

}

# Run the application 

shinyApp(ui = ui, server = server)

In the server function, it is always throwing me an error telling lamda not found. So I tried to define lamda as shown below:

n = 1234

#Exponencial

lambda1 <- 7 ; rate <- 5

S1 <- actuar::rcompound(n = n, #Genera n

               model.freq = rpois(lambda = lambda1), #N~Poi(lambda1)

               model.sev = rexp(rate = rate)) #Y~Exp(rate) 

Answer 1

I have gone through your code I didn't find any errors. My suggestion is to assign the lambda1 in a global environment. Like this:

lambda1 <<- input$lambda1

Instead of using a package, you can use your own rcoumpound function.

Linke this:

rcompound <- function(n, lambda, rate){

  N <- rpois(n, lambda)

  vapply(N, function(k) sum(rexp(k, rate = rate)), numeric(1))

}

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