Using r shiny inputs to run a r script-CodePudding

I have already made a r script to calculate queue times using queuing theory but now I wish to make a ui/website where the user can input information like number of people and service time then run the r script I made to give the user the output. But I am unable to get the input from the r shiny website to the r script I made because the values are not coming up in the global variables list. Here is the code so far:

library(shiny)
ui <- fluidPage(

h1("This is a test input"),
numericInput("Lambda","Enter people coming in",20),
actionButton("runScript", "Run")
)

server <- function(input, output, session){
mylist <- reactiveVal() 
observe({ 
mylist(list(
  Lambda = input$Lambda))
 })
observeEvent(input$runScript, { 
source("algo.R", local = list2env(mylist()))
})

}
shinyApp(ui = ui, server = server)

the queuing theory script

Lambda <- Lambda

Mue <- 4

Rho <- Lambda/Mue
matrix <- matrix(0,10,2)
matrix[,1] <- 1:10
calculatewq <- function(c){
P0inv <- Rho^c/(factorial(c)*(1-(Rho/c)))
for (i in 1:c-1) {
  P0inv = P0inv   (Rho^i)/factorial(i)
}
P0 = 1/P0inv
Lq = (Rho^(c 1))*P0/(factorial(c-1)*(c-Rho)^2)
Wq = 60*Lq/Lambda
Ls <- Lq   Rho
Ws <- 60*Ls/Lambda
#print(paste(Lq," is queue length and ",Wq," is the waiting time"))
a <- cbind(Lq,Wq,Ls,Ws)
return(a)
     }
for (i in 1:10){
       matrix[i,2] <- calculatewq(i)[2]
    }

What do I need to do so that I can take two inputs from the r shiny website and then use those inputs in the r script then display the matrix that comes out in the end.

CodePudding user response：

To elaborate on my comment:

library(shiny)

myScriptFunction <- function(Lambda) {
  Mue <- 4

  Rho <- Lambda/Mue
  matrix <- matrix(0,10,2)
  matrix[,1] <- 1:10
  calculatewq <- function(c){
    P0inv <- Rho^c/(factorial(c)*(1-(Rho/c)))
    for (i in 1:c-1) {
      P0inv = P0inv   (Rho^i)/factorial(i)
    }
    P0 = 1/P0inv
    Lq = (Rho^(c 1))*P0/(factorial(c-1)*(c-Rho)^2)
    Wq = 60*Lq/Lambda
    Ls <- Lq   Rho
    Ws <- 60*Ls/Lambda
    #print(paste(Lq," is queue length and ",Wq," is the waiting time"))
    a <- cbind(Lq,Wq,Ls,Ws)
    return(a)
  }
  for (i in 1:10){
    matrix[i,2] <- calculatewq(i)[2]
  }
  matrix
}

ui <- fluidPage(
  h1("This is a test input"),
  numericInput("Lambda","Enter people coming in",20),
  actionButton("runScript", "Run"),
  tableOutput("result")
)

server <- function(input, output, session){
  mylist <- reactiveVal() 
  observe({ 
    mylist(list(
      Lambda = input$Lambda))
  })

  output$result <- renderTable({
    input$runScript
    
    isolate(as.data.frame(myScriptFunction(input$Lambda)))
  })
}

shinyApp(ui = ui, server = server)

You could also eliminate the actionButton entirely and have the output update immediately the selectInput is changed by using:

  output$result <- renderTable({
    as.data.frame(myScriptFunction(input$Lambda))
  })