title: Why does my ROC curve look like a V?
body: <p><a href="https://i.stack.imgur.com/0Lhrl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0Lhrl.png" alt="ROC CURVE via ROCR"></a>   </p>
  
  <pre><code>newpred &lt;- c(1, 0 ,0 ,1 ,0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0,
  0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0,0, 1, 0, 0,
  0, 0,0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0,
   0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0,  
   1,0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1,
   1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0)                    
  
  
         newlab &lt;- c(0, 0 ,0 ,0 ,0 ,0 ,0 ,1 ,0 ,0 ,0 ,0 ,0 ,0,
                     0, 0 ,0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                     0 ,0, 1, 1, 0, 0, 0, 0, 0, 0, 1,
                      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                      0, 1 ,0, 0 ,0, 0 ,0, 0 ,1, 0 ,0, 0 ,0, 0 ,0,
                     0, 0 ,1 ,0 ,0 ,0 ,0 ,0 ,0 ,1,
                      0 ,1, 0 ,1, 0 ,0, 0 ,0, 0 ,0, 0 ,0, 0 ,0, 0 ,0)
  </code></pre>
  
  <p>So the first vector are my predictions and the second vector is the reference. I don't understand why my curve looks like a V. I've never seen a ROC curve look like this! My advisor wants me to add points to make the graph smoother/more curved by adding more points. I tried to graph using pROC but the only arguments I could add were prediction and reference. </p>
  
  <p>I also tried with ROCR </p>
  
  <pre><code>print.cutoffs.at=seq(0,1,by=0.1), text.adj=c(-0.2,1.7))
  </code></pre>
  
  <p>and got this
  <a href="https://i.stack.imgur.com/JSVDe.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JSVDe.png" alt="enter image description here"></a></p>
  
  <p>How do I smooth the curve or add more points?</p>