It looks to me like the lines (10k, 3 segments each) are slower than the 30k segments. The reason is that the Qt API forces each line to be drawn separately, while segments can be drawn in batch. We use Qt for all line drawing. <br>
<br>The only reason to use lines is if the line width is > 0, and thus line joining matters. That suggests one possible optimization, purely at the R level.<br><br>Michael<br><br><div class="gmail_quote">On Tue, Mar 23, 2010 at 7:18 AM, Hadley Wickham <span dir="ltr"><<a href="mailto:hadley@rice.edu">hadley@rice.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div class="im">>> * what is up with antialiased segments?!<br>
>><br>
> Might need to be more specific? Software is very slow when drawing<br>
> antialiased segments.<br>
<br>
</div>I just meant they are incredibly slow - why is there such a different<br>
between segments and lines?<br>
<div><div></div><div class="h5"><br>
Hadley<br>
<br>
--<br>
Assistant Professor / Dobelman Family Junior Chair<br>
Department of Statistics / Rice University<br>
<a href="http://had.co.nz/" target="_blank">http://had.co.nz/</a><br>
</div></div></blockquote></div><br>