title: Large TChart takes a long time to draw
body: <p>Top post: I have accepted an answer,but it doesn't work for me. I will post <a href="https://stackoverflow.com/questions/4782560/optimizing-tchart-drawing-in-delphi-7">a new question</a>, stressing Delphi 7. Thanks to all who gave some good input  </p>
  
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  <p>I have measurements taken at one second intervals over an hour.</p>
  
  <p>I had a previous question where it was taking 45 seconds to updates a TStringGrid and managed to get that down to "faster than the eye can see". Partly by moving some computation and database related functionality of of the loop, but - surprisingly to me - the change that really made the difference was setting the strindgrid's rowCount to 3600 before the loop rather than incrementing it inside the loop.</p>
  
  <p>Now I have a similar problem with a TChart. Maybe if I try preallocating the chart? So, I could <code>Chart1.Series[0].Count := 3600</code>, but than I can't use <code>AddXy()</code> or <code>Add()</code>, so how would I explicitly set the values in series? </p>
  
  <p>I have a very simple chart, with Floats on the y-axis and hour:seconds on the x-axis</p>
  
  <p>Can anyone help, or suggest another way to speed up chart drawing?</p>
  
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  <p>Update: several have suggested using <code>TFastLineSeries</code>, but I don't see how.</p>
  
  <p>Aha - double click on the Chart, to show all series, select one &amp; click change</p>