title: jitter geom_line()
body: <p>Is there a way to jitter the lines in <code>geom_line()</code>? I know it kinda defies the purpose of this plot, but if you have a plot with few lines and would like them all to show it could be handy. Maybe some other solution to this <em>visibility</em> problem.</p>
  
  <p>Please see below for code,
  <img src="https://i.stack.imgur.com/tusNp.png" alt="jitter geom_line"></p>
  
  <pre><code>A  &lt;- c(1,2,3,5,1)
  B  &lt;- c(3,4,1,2,3)
  id &lt;- 1:5
  df &lt;- data.frame(id, A, B)
  
  
  # install.packages(reshape2)
  require(reshape2) # for melt
  dfm &lt;- melt(df, id=c("id"))
  
  # install.packages(ggplot2)
  require(ggplot2)
  p1 &lt;- ggplot(data = dfm, aes(x = variable, y = value, group = id, 
  color= as.factor(id))) + geom_line() + labs(x = "id # 1 is hardly 
  visible as it is covered by id # 5") + scale_colour_manual(values = 
  c('red','blue', 'green', 'yellow', 'black')) 
  
  
  p2 &lt;- ggplot(subset(dfm, id != 5), aes(x = variable, y = value, 
  group = id, color= as.factor(id))) + geom_line() + labs(x = "id # 
  5 removed, id # 1 is visible") + scale_colour_manual(values = 
  c('red','blue', 'green', 'yellow', 'black')) 
  
  # install.packages(RODBC)
  require(gridExtra)
  
  grid.arrange(p1, p2)
  </code></pre>