title: R: ggplot display all dates on x axis
body: <p>I have the following data set</p>
  
  <pre><code>structure(list(Date = structure(c(16636, 16667, 16698, 16728, 
  16759, 16789, 16820, 16851, 16880, 16911, 16636, 16667, 16698, 
  16728, 16759, 16789, 16820, 16851, 16880, 16911, 16636, 16667, 
  16698, 16728, 16759, 16789, 16820, 16851, 16880, 16911, 16636, 
  16667, 16698, 16728, 16759, 16789, 16820, 16851, 16880, 16911, 
  16636, 16667, 16698, 16728, 16759, 16789, 16820, 16851, 16880, 
  16911), class = "Date"), Wheel = structure(c(5L, 5L, 5L, 5L, 
  5L, 5L, 5L, 5L, 5L, 5L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 
  12L, 12L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 11L, 11L, 11L, 
  11L, 11L, 11L, 11L, 11L, 11L, 11L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 
  6L, 6L, 6L), .Label = c("L1", "L2", "L3", "L4", "L5", "L6", "R1", 
  "R2", "R3", "R4", "R5", "R6"), class = "factor"), WearRate = c(-0.000367, 
  0, 0, 0, 0.001888, 0, -0.00018, 0.000579, -0.000211, 0.000643, 
  0.000106, 0, 0, 0, 0.000833, 0, -0.00036, 0.000811, -0.000819, 
  0.002044, -0.00029, 0, 0, 0, 0.001666, 0, -0.000348, 0.000888, 
  -0.000679, 0.001636, 8.7e-05, 0, 0, 0, 0.000666, 0, -0.000315, 
  0.000618, -0.000585, 0.001636, -0.000512, 0, 0, 0, 0.002499, 
  0, -0.000247, 0.000734, -9.4e-05, 0.000409)), .Names = c("Date", 
  "Wheel", "WearRate"), row.names = 211269:211318, class = "data.frame")
  </code></pre>
  
  <p>I am trying to make a plot of <code>Date vs WearRate</code> and <code>color by Wheel</code>. The code is as follows:</p>
  
  <pre><code>ggplot(data = df) + geom_point(mapping = aes(x = Date, y = WearRate, color = Wheel))
  </code></pre>
  
  <p>It works but I want to put actual date labels. How do I do it?</p>
  
  <p><strong>Edit</strong></p>
  
  <p>The plot currently looks as shown here. However, I want to see "Aug 2015", "Sep 2015" etc on X axis and I want to display all the ticks.</p>
  
  <p><a href="https://i.stack.imgur.com/PAuK9.png" rel="noreferrer"><img src="https://i.stack.imgur.com/PAuK9.png" alt="enter image description here"></a></p>