Plot multiple ROC curves on one plot?
<p>I want to cycle compare several logistic regression models.
And print in one chart several ROC curves.
How I can do this?
For example, for one model it looks like</p>

<pre><code>pred_fit4 &lt;- prediction(workData$pred,workData3$value)
perf_fit4 &lt;- performance(pred_fit4,"tpr","fpr")
roc &lt;- plot(perf_fit4,colorize = T, print.cutoffs.at = seq(0,1),)
</code></pre>

<p>and its curve output as below:</p>

<p><a href="https://i.stack.imgur.com/dJoZv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dJoZv.png" alt="enter image description here"></a></p>

<p>And how can I add a new line?
It looks like</p>

<pre><code>for (...) {
.......
.......
    pred_fit4 &lt;- prediction(workData$pred,workData3$value)
    perf_fit4 &lt;- performance(pred_fit4,"tpr","fpr")
    #need add line on exist chart
    roc &lt;- plot(perf_fit4,colorize = T , print.cutoffs.at = seq(0,1),)
}
</code></pre>