how to reduce the file size of plots generated with matplotlib

Community matplotlib-users
1

I think what the responders have in mind is simply outputting files in a
different format, e.g. png, which is rasterized. One alternative you might
consider is using code written by Tom Robataille called rasterized_scatter.
It automatically rasterizes your data points. You can find it on github.

Jon

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On Sat, Mar 22, 2014 at 4:39 PM, < matplotlib-users-request@lists.sourceforge.net> wrote:

From: Christopher Kuhlman <ckuhlman@...4505...>
To: Goyo <goyodiaz@...287...>
Cc: matplotlib-users <matplotlib-users@lists.sourceforge.net>
Date: Sat, 22 Mar 2014 16:38:59 -0400 (EDT)
Subject: Re: [Matplotlib-users] how to reduce the file size of plots
generated with matplotlib
Thank you both for your fast replies. (Just an aside, plotting all the
points is a quick way to detect outliers.)

Before I sent the email, I tried to find a simple raster command in
matplotlib to do just that (convert the image to raster), but I could not
find one in my search. Is there such a thing?

Thanks again.

c

----- Original Message -----
From: "Goyo" <goyodiaz@...287...>
To: "Christopher Kuhlman" <ckuhlman@...4505...>
Cc: "matplotlib-users" <matplotlib-users@lists.sourceforge.net>
Sent: Saturday, March 22, 2014 4:11:08 PM
Subject: Re: [Matplotlib-users] how to reduce the file size of plots
generated with matplotlib

2014-03-22 20:23 GMT+01:00 Christopher Kuhlman <ckuhlman@...4505...>:
[...]
> For example, most recently, I am plotting 3 data sets; each data set has
about 90,000 points. If I plot all three sets in one PDF figure, the file
size is over 2MB.
> This seems absurd to me. I used R plotting for many years (again, my
own homegrown code, for 6 years) and never had this issue, and I was making
these kinds of plots/figures.
>
> I thought it may be a vector/raster issue, but the following web page
says that PDF are generated as vector image, which, to my understanding
(which could be wrong), is the more compact format.
> http://matplotlib.org/faq/usage_faq.html
[...]

Roughly speaking, size of vector files depend on the number of points
while size of raster files depends on the number of pixels. For your
use case (many points, small images) raster output should be more
compact.

Goyo

--
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Jonathan D. Slavin Harvard-Smithsonian CfA
jslavin@...1081... 60 Garden Street, MS 83
phone: (617) 496-7981 Cambridge, MA 02138-1516
fax: (617) 496-7577 USA
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