title: ggplot2 confusion
body: <p>Hi can anyone tell me whats wrong with following R code?</p>
  
  <pre><code>ggplot(train, aes(x= Item_Visibility, y = Item_Outlet_Sales)) + 
  geom_point(size = 2.5, color="navy") + 
  xlab("Item Visibility") + 
  ylab("Item Outlet Sales") + 
  ggtitle("Item Visibility vs Item Outlet Sales")
  </code></pre>