title: R and Shiny: Pass inputs from sliders to reactive function to compute output
body: <p>I have 6 parameters that the user can change values for. These are our 6 inputs. 
  I want to create an output value that takes those 6 inputs and computes our value of interest given a number of related equations in a function. Here is what I have in my UI...</p>
  
  <pre><code>library(shiny)
  
  # Define UI for slider demo application
  shinyUI(pageWithSidebar(
  
  #  Application title
  headerPanel("# Header Title Goes Here"),
  
  # Sidebar with sliders that demonstrate various available options
  sidebarPanel(
  # Simple integer interval
  sliderInput("u1", "Name:", 
              min=0, max=10000, value=10000),
  #There are 6 slider inputs...
  
      ),
  
  # Show a table summarizing the values entered
  mainPanel(
   tableOutput("values"),
  
   uiOutput("focal"))
   )
  )  
  </code></pre>
  
  <p>Here is what I have in my server.R...</p>
  
  <pre><code>library(shiny)
  
  shinyServer(function(input, output) {
  
  # Reactive expression to compose a data frame containing all of the values
  sliderValues &lt;- reactive({
  
  # Compose data frame
  data.frame(
    Name = # Names of my 6 parameters,
  
    Value = # inputs based on my 6 values by `input$value`,
  
    stringsAsFactors=FALSE)
  })
  
  f &lt;- renderText({function(r1, r2, r3, d1, d2, u1) #these are my 6 values
  { #List of equations that compute f based on the 6 values
  }
  })
  
  
  # Show the values using an HTML table
  output$values &lt;- renderTable({
  sliderValues()
  })
  
  # Show the final calculated value 
  output$focal &lt;- renderText({
  f
  })
  })
  </code></pre>
  
  <p>I keep getting... Error: argument 1(type 'closure') cannot be handled by 'cat'
  and many other errors. I just don't how to transfer the updated user inputs of the 6 parameters to my function and spit that function back out in the output area on the Shiny html page. </p>
  
  <p>Any help would be greatly appreciated!! </p>
  
  <p>Thanks!</p>