Fix: Resolve factor conversion error in randomForest model

shiny/003-play-golf/app.R

@@ -12,8 +12,18 @@ library(data.table)
 library(RCurl)
 library(randomForest)
 
-# Read data
-weather <- read.csv(text = getURL("https://raw.githubusercontent.com/dataprofessor/data/master/weather-weka.csv") )
+# Read data, at first I got an error message stating,
+# Error in y - ymean : non-numeric argument to binary operator
+# Until I put in line 20 and lines 23-25. Fixed bug.
+weather <- read.csv(
+  text = getURL("https://raw.githubusercontent.com/dataprofessor/data/master/weather-weka.csv"),
+  stringsAsFactors = FALSE
+)
+
+weather$play <- as.factor(weather$play)
+weather$outlook <- as.factor(weather$outlook)
+weather$windy <- as.factor(weather$windy)
+
 
 # Build model
 model <- randomForest(play ~ ., data = weather, ntree = 500, mtry = 4, importance = TRUE)
@@ -29,35 +39,35 @@ model <- randomForest(play ~ ., data = weather, ntree = 500, mtry = 4, importanc
 ####################################
 
 ui <- fluidPage(theme = shinytheme("united"),
-
+                
   # Page header
   headerPanel('Play Golf?'),
-
+                
   # Input values
   sidebarPanel(
-    HTML("<h3>Input parameters</h3>"),
-
-    selectInput("outlook", label = "Outlook:", 
-                choices = list("Sunny" = "sunny", "Overcast" = "overcast", "Rainy" = "rainy"), 
-                selected = "Rainy"),
-    sliderInput("temperature", "Temperature:",
-                min = 64, max = 86,
-                value = 70),
-    sliderInput("humidity", "Humidity:",
-                min = 65, max = 96,
-                value = 90),
-    selectInput("windy", label = "Windy:", 
-                choices = list("Yes" = "TRUE", "No" = "FALSE"), 
-                selected = "TRUE"),
-
-    actionButton("submitbutton", "Submit", class = "btn btn-primary")
+  HTML("<h3>Input parameters</h3>"),
+                  
+  selectInput("outlook", label = "Outlook:", 
+              choices = list("Sunny" = "sunny", "Overcast" = "overcast", "Rainy" = "rainy"), 
+              selected = "Rainy"),
+  sliderInput("temperature", "Temperature:",
+              min = 64, max = 86,
+              value = 70),
+  sliderInput("humidity", "Humidity:",
+              min = 65, max = 96,
+              value = 90),
+  selectInput("windy", label = "Windy:", 
+              choices = list("Yes" = "TRUE", "No" = "FALSE"), 
+              selected = "TRUE"),
+                  
+  actionButton("submitbutton", "Submit", class = "btn btn-primary")
   ),
-
+                
   mainPanel(
-    tags$label(h3('Status/Output')), # Status/Output Text Box
-    verbatimTextOutput('contents'),
-    tableOutput('tabledata') # Prediction results table
-
+  tags$label(h3('Status/Output')), # Status/Output Text Box
+  verbatimTextOutput('contents'),
+  tableOutput('tabledata') # Prediction results table
+                  
   )
 )
 
@@ -66,35 +76,26 @@ ui <- fluidPage(theme = shinytheme("united"),
 ####################################
 
 server <- function(input, output, session) {
-
+
+
+  # Refactored the 'datasetInput' reactive expression
   # Input Data
   datasetInput <- reactive({  
 
-  # outlook,temperature,humidity,windy,play
-  df <- data.frame(
-    Name = c("outlook",
-             "temperature",
-             "humidity",
-             "windy"),
-    Value = as.character(c(input$outlook,
-                           input$temperature,
-                           input$humidity,
-                           input$windy)),
-    stringsAsFactors = FALSE)
-
-  play <- "play"
-  df <- rbind(df, play)
-  input <- transpose(df)
-  write.table(input,"input.csv", sep=",", quote = FALSE, row.names = FALSE, col.names = FALSE)
-
-  test <- read.csv(paste("input", ".csv", sep=""), header = TRUE)
-
-  test$outlook <- factor(test$outlook, levels = c("overcast", "rainy", "sunny"))
-
-
-  Output <- data.frame(Prediction=predict(model,test), round(predict(model,test,type="prob"), 3))
-  print(Output)
-
+    # Create the dataframe with correct types immediately
+    test <- data.frame(
+      outlook = factor(input$outlook, levels = levels(weather$outlook)),
+      temperature = as.numeric(input$temperature),
+      humidity = as.numeric(input$humidity),
+      windy = factor(input$windy, levels = levels(weather$windy))
+    )
+
+    # Generate prediction
+    Output <- data.frame(
+      Prediction = predict(model, test), 
+      round(predict(model, test, type = "prob"), 3)
+    )
+    print(Output)
   })
 
   # Status/Output Text Box
@@ -118,4 +119,4 @@ server <- function(input, output, session) {
 ####################################
 # Create the shiny app             #
 ####################################
-shinyApp(ui = ui, server = server)
+shinyApp(ui = ui, server = server) `