title: connecting points in plot in R
body: <p>this is a simple task but for some reason it is not giving me the desired output.</p>
  
  <pre><code>x1 = c(100000,250000,500000,750000,1000000)
  y1 = c(1.076904,3.917412,12.365130,23.084268,37.234246)
  plot(y1, pch=5, ylim=c(1,50),xlab="Sample Size", ylab="Time(s)" , main = "Time relative to Sample Size-NonGreedy", xaxt = "n")
  axis(1, at=1:5, labels = x1)
  lines(x1,y1, col = "gray")
  </code></pre>
  
  <p>I want to plot x1,y1 and connect the points with a line, but the line is not 
  showing. 
  I am using axes because I want these specific labels to show. </p>
  
  <p>Any recommendations?</p>