[reportlab-users] Performance problem for lineplots with many values (with possible solution)

[Sebastian Messing]

Hi!

I tried to generate a lineplot with joinedLines=1. The lineplot has 
three lines, each line with 86000 values. The generation of the lineplot 
is very, very slow (hours).

I use ReportLab 2.6 but I also found the problem in ReportLab daily from 
01/29/2013 in /src/reportlab/graphics/charts/lineplots.py:
276  # Iterate over data columns.
277  if self.joinedLines:
278      points = []
279      for xy in row:
280          points += [xy[0], xy[1]]

If I use a list comprehension instead, the plot is generated within 
seconds or minutes:
278  points = [[xy[0], xy[1]] for xy in row]
279
280

Also linecharts.py contains the same performance problem but I don't use 
that.

Best regards
Sebastian Messing
-- 
OsTech GmbH i.G.
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Tel.: 030/2977304-23
Fax: 030/2977304-11