[reportlab-users] Performance problem for lineplots with many values (with possible solution)
sebastianmessing at gmx.de
Wed Jan 30 05:17:10 EST 2013
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, xy]
If I use a list comprehension instead, the plot is generated within
seconds or minutes:
278 points = [[xy, xy] for xy in row]
Also linecharts.py contains the same performance problem but I don't use
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