What function space is the field that you're saving? If it's not fully continuous then we output the data as fully discontinuous, which might have some redundancy. [I'll remark that 100*100*100*(8 bytes/double) is already ~8MB, so that's only a factor of 25. Since the mesh data is also there, multiply that 8MB by (1 + 3).] On 30 May 2016 at 15:09, Francis Poulin <fpoulin@uwaterloo.ca> wrote:

Hello Lawrence,

In a case with 100x100x100, each field seems to be taking up about 200 MB. I talked to someone who is saving things in binary and they thought this was probably too big by a factor of 50 or so. I'm not sure how much space it should take but if it's possible to be more compact that would be nice. I can compress things afterwards but in my experience binary files usually don't compress that much, but I could be wrong.

Cheers, Francis

------------------ Francis Poulin Associate Professor Department of Applied Mathematics University of Waterloo

email: fpoulin@uwaterloo.ca Web: https://uwaterloo.ca/poulin-research-group/ Telephone: +1 519 888 4567 x32637

________________________________________ From: firedrake-bounces@imperial.ac.uk [firedrake-bounces@imperial.ac.uk] on behalf of Lawrence Mitchell [lawrence.mitchell@imperial.ac.uk] Sent: Monday, May 30, 2016 9:54 AM To: firedrake@imperial.ac.uk Subject: Re: [firedrake] saving vtu files in binary

Dear Francis,

...

On 30 May 2016, at 14:43, Francis Poulin <fpoulin@uwaterloo.ca> wrote:

Hello,

I have noticed that the vtu files that I'm creating in firedrake tend to be big. I presume this is because they are being saved in ascii format. Is it easy to save these files in binary to be a bit more space efficient?

Actually, only the metadata is saved in ascii format. The actual bulk data is saved in binary (although, to be fair, it's uncompressed). Unfortunately due to limitations in the vtu file format, the mesh description must be saved in every file (even when it doesn't change) which makes for some size increases. Are the vtus you get much larger than you're expecting? Or is is just that you'd like them to be smaller?

Cheers,

Lawrence

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