shiny slider inputs to named list

Question

So I'm a bit new to Shiny, but cannot for the life of me, figure out how to get the slider input values organized into a named list. Right now, I have a UI set up that allows for 11 inputs.

library(shiny)

shinyUI(pageWithSidebar(
  headerPanel("Quorom Sensing Model"),
  sidebarPanel(
sliderInput("n", "Hill Coefficient:", 
            min=0, max=10, value=2, step=0.5),
sliderInput("K", "Max Contribution to lacI transcription:", 
            min=0, max=50, value=20, step=1),
sliderInput("k0_AI", "Initial Synthesis Rate of AI:", 
            min=0, max=5, value=3.5, step=0.1),
sliderInput("k1_AI", "Repressor dependent rate of synthesis of AI:", 
            min=0, max=1, value=.033, step=0.001),
sliderInput("eta", "diffusion rate of AI across cell membrane:", 
            min=0, max=5, value=.7, step=0.1),
sliderInput("k_deg", "extracellular AI degredation Rate:", 
            min=0, max=1, value=.525, step=0.001),
sliderInput("k_diff", "extracellular diffusion rate of AI:", 
            min=0, max=10, value=2.1, step=0.1),
sliderInput("alpha_tetR", "Alpha tetR:", 
            min=0, max=50, value=24, step=1),
sliderInput("alpha_cI", "Alpha cI:", 
            min=0, max=50, value=24, step=1),
sliderInput("alpha_lacI", "Alpha lacI:", 
            min=0, max=50, value=24, step=1),
sliderInput("beta", "Ratio of protein decay to mRNA decay rate:", 
            min=0, max=10, value=1.05, step=0.05)
  ),
  mainPanel(
plotOutput("timeSeries"),
plotOutput("timeSeries2")
 )) 
)

So these slider inputs need to feed into a named list, where parameters (the named list) = c(n = the value of input$n, K = input$K, etc) so that I can feed the named number list into a function that does the math required to generate the outputs.

Right now, I have the function params, which returns a named list based on the input variables:

params <- function(n = 2, 
               K=20, 
               k0_AI=3.5, 
               k1_AI=0.033, 
               eta=0.7,
               k_deg=0.525, 
               k_diff=2.1, 
               alpha_tetR=24,
               alpha_cI=24,
               alpha_lacI=24,
               beta=1.05){
  paramlist <- c(n = n, 
             K = K, 
             k0_AI = k0_AI, 
             k1_AI = k1_AI, 
             eta = eta,
             k_deg = k_deg, 
             k_diff = k_diff, 
             alpha_tetR = alpha_tetR,
             alpha_cI = alpha_cI,
             alpha_lacI = alpha_lacI,
             beta = beta)
  return(paramlist)

}

Which is is called from the server.R and the input variables are set to the input$etc from the sliders?

library(shiny)
library(ggplot2)
library(reshape2)
library(deSolve)
source("params.R")
shinyServer(function(input,output){


parameters = reactive({
        params(n =  input$n, 
         K = input$K, 
         k0_AI = input$k0_AI, 
         k1_AI= input$k1_AI, 
         eta = input$eta,
         k_deg = input$k_deg, 
         k_diff = input$k_diff, 
         alpha_tetR = input$alpha_tetR,
         alpha_cI = input$alpha_cI,
         alpha_lacI =input$alpha_lacI,
         beta = input$beta
    )
})

Error in eval(substitute(expr), data, enclos = parent.frame()) : invalid 'envir' argument of type 'closure'

Again, I need the input sliders values to be part of a named list where the name of the slider = the value and the name of the list can be called from a function. How could I do this most easily? Thanks!

John Paul John Paul · Accepted Answer · 2014-12-22T20:43:27

I think this 2 step process will work.

First - make a reactiveValues object to hold all this. You can add values as you go along:

Values <- reactiveValues()
Values$n <- input$n
Values$K <- input$K

and so on.

Then use reactiveValuesToList to make the list

reactiveValuesToList(Values)

The list will have the names you might expect. The Values$K value will be named "K" and so on. You can just put that where you need the list.

shiny slider inputs to named list

1 Answers