title: JPGraph error, A plot has an illegal scale
body: <p>I'm trying to make a graph with JPGragph, but I keep getting an error saying:</p>
  
  <pre><code>JpGraph Error A plot has an illegal scale. This could for example be that you are trying to use text auto scaling to draw a line plot with only one point or that the plot area is too small. It could also be that no input data value is numeric (perhaps only '-' or 'x')
  
  $ydata = round($ydata[0]); // An attempt to convert float to int
  $ydata = (int)$ydata; // That didn't bring any solution(thought it couldn't handle float)
  
  $pt = new LinePlot($ydata); // Here is where the error is thrown
  $bar2-&gt;Add($pt);
  $pt-&gt;SetColor("blue");
  $pt-&gt;SetWeight(10);
  </code></pre>
  
  <p>I've tried to replace $ydata with an integer, but that only throws an fatal error.</p>
  
  <p>Without the round and type cast, this is the var_dump of $ydata:</p>
  
  <pre><code>array(1) { [0]=&gt; float(8.1102970953135) }
  </code></pre>