title: Formatting ggplot2 gaphis - manhattan plot
body: <p>I did programm the following graphs in R, using the ggplot2 package.
  But some details I could not change.</p>
  <p><a href="https://i.stack.imgur.com/JjXNg.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JjXNg.jpg" alt="enter image description here" /></a></p>
  <p>To do this, I use the follow programming:</p>
  <pre><code>b=ggplot(data1,aes(pos,P),group =CHR) + geom_point(size=1, aes(color=CHR)) +
  guides(fill=FALSE) + 
  geom_hline(yintercept=20,colour=&quot;green&quot;, alpha=I(2/3)) +
  geom_hline(yintercept=150,colour=&quot;red&quot;, alpha=I(3/3))
  b+ scale_x_discrete(&quot;Chromosome&quot;, labels = c(1:27))
  </code></pre>
  <p>1º: I want to remove the scale legend of &quot;chromosome&quot;. I put the <code>guides(fill=FALSE)</code>, but did not solve.</p>
  <p>2º: I want to put the delimitations of x axis of each chromosome. To try this I put: <code>scale_x_discrete(&quot;Chromosome&quot;, labels = c(1:27))</code>. But did not solve the problem.</p>
  <p>3º: On label chromosome have a big thick black belt. I want remove this.</p>
  <p>Thank you.</p>