Ising example

global.R

library("qgraph")
library("igraph")
library("Rcpp")
library("shiny")

download.file("http://sachaem47.fortyseven.versio.nl/files/IsingCppBinary.cpp", file <- tempfile(fileext=".cpp"))
sourceCpp(file)

server.R

shinyServer(function(input, output) {
    
  # Network parameters:
  J <- reactive({
    network <- matrix(input$net,input$nNodes,input$nNodes)
    diag(network) <- 0
    return(network)
  })
  
  h <- reactive({
    return(rep(input$thresh, input$nNodes))
  })
  
  AllStates <- reactive({
    return(do.call(expand.grid,lapply(1:input$nNodes,function(x)c(0L,1L))))
  })
  
  output$adjplot <- renderPlot({
    qgraph(J(),weighted=FALSE)
  })
  
  ### State distribution:
  output$statedist <- renderTable({
    
    Dist <- exp(-input$beta * apply(AllStates(),1,function(s)H(J(),s,h())))  
    Dist <- Dist/sum(Dist)
    
    ### Return:
    return(cbind(AllStates(), P = Dist))
  })
  
  ### State distribution:
  output$endist <- renderPlot({
    En <- apply(AllStates(),1,function(s)H(J(),s,h()))
    
    layout(1:2)
    curve(exp(-input$beta * x), min(En), max(En), yaxt = "n", xlab = "Energy", ylab = "Probability", bty = "n")
    hist(En, breaks = 16, xlim=c( min(En), max(En)), xlab = "Energy", ylab = "Number of states", main = "")  

  })
  
  
  # Sumscore distribution:
  output$sumdist <- renderPlot({
    
    Dist <- IsingDirLik(Graph = J(), Thresholds = h(), Beta = input$beta)
    barplot(Dist$P, names.arg = Dist$Sum)
    
  },width='auto',height='auto')
  

  
  
  
  # Plotting window:
  output$window <- renderUI({
      if (input$show == 'Sumscore distribution')
      {
        plotOutput('sumdist', width = 1000, height = 500)
      } else if (input$show == 'State distribution')
      {
        tableOutput('statedist')
      } else 
      {
        plotOutput('endist', width = 1000, height = 1000)
      }
  })
  
})

ui.R

shinyUI(pageWithSidebar(
  
  # Header:
  headerPanel("Ising example (fully connected network)"),
  
  # Input in sidepanel:
  sidebarPanel(
    
    sliderInput("nNodes", "Number of Nodes:", 
                min=1, max=10, value=2, step = 1),
    sliderInput("net", "Network Strength:", 
                min=0, max=10, value=1, step = 0.1),
    sliderInput("thresh", "External Field:", 
                min=-10, max=0, value=-1, step = 0.1),  
    sliderInput("beta", "Inverse Temperature:", 
                min=0.1, max=5, value=1, step = 0.1),
    
    br(),
    
    plotOutput("adjplot",'100%')


    
    ),
  
  # Plot in main:
  mainPanel(
    # Show a plot of the generated distribution
    radioButtons("show", "Show:",
                 c('Sumscore distribution','State distribution','Energy distribution')),
    
    htmlOutput("window")
  )
))