title: Plot with conditional colors based on values in R
body: <p>I want to plot a graph with different colors based on values. I wrote the below code, </p>
  
  <pre><code>np_graph &lt;- data.frame(C1 = -5:5, C2 = -5:5)
  x=np_graph2$C1
  y=np_graph2$C2
  plot(x,y,xlab="PC1",ylab="PC2")
  </code></pre>
  
  <p>Now, if the value of X is >0, then that value should be in green (in the graph). if the value of Y is >0, then that value should be in red (in the graph).</p>
  
  <p>Can some one help me in this?</p>