title: invalid line type: must be length 2, 4, 6 or 8
body: <p>I am using segments for drawing line but i need little bit more control on line type. SO I am using lty="1" but i get error message.  I am using code below.</p>
  
  <pre><code>segments(593, 20.65+.06, 593+3, 20.65+.06, col= "black", lty="1")
  </code></pre>
  
  <p>But i am getting following error message.</p>
  
  <pre><code>  Error in segments(593, 20.65 + 0.06, 593 + 3, 20.65 + 0.06, col = "black",  : 
    invalid line type: must be length 2, 4, 6 or 8
  </code></pre>
  
  <p>I just need to control line type mentioned in lty().How can i fix this problem? </p>