title: Adjusting y-axis line position in ggplot2
body: <p>I'm trying to remove the space between the y-axis line and the first tick mark in my plot. Here's an example:</p>
  
  <pre><code>set.seed(201)
  n &lt;- 100
  dat &lt;- data.frame(xval = (1:n+rnorm(n,sd=5))/20, yval = 2*2^((1:n+rnorm(n,sd=5))/20))
  dat[dat[,1] &lt; 0,1] &lt;- 0
  dat[dat[,2] &lt; 0,2] &lt;- 0
  
  ggplot(dat, aes(xval, yval)) + geom_point()
  </code></pre>
  
  <p>This code plots a graphic with a space between the y-axis line and the zero tick mark in the x-axis. How can I remove it?</p>