title: melt, not as.data.frame or rbind in R (basic ggplot)
body: <p>I have several equal-length vectors of numbers, like </p>
  
  <pre><code>alpha &lt;- c(1, 2, 3, 4)
  beta &lt;- c(5, 6, 7, 8)
  gamma &lt;- c(9, 10, 11, 12)
  </code></pre>
  
  <p>and I want to put these into a data frame or something with columns labelled alpha, beta, and gamma. Like</p>
  
  <pre><code>alpha | beta | gamma
  1 | 5 | 9
  2 | 6 | 10
  3 | 7 | 11
  4 | 8 | 12
  </code></pre>
  
  <p>which <code>qplot</code> should be able to read and separate out by <code>colour = labels</code>. <code>cbind</code> and <code>rbind</code> result in a matrix which <code>qplot</code> cannot read. And <code>c</code> lines up alpha beta and gamma, without labelling them as separate.</p>
  
  <p>The <code>diamonds</code> data set displays what I'm after with <code>qplot(carat, price, data = diamonds, colour = color)</code> except I want to plot my shared-dimensional data against an index like <code>x=1:4</code>.</p>
  
  <p>In regular <code>R</code> I would do <code>plot(alpha); points(beta); points(gamma)</code>.</p>
  
  <p>Sorry for asking such a basic question.</p>