[yt-users] How to efficiently control the memory in yt with large simulation?

[Junhwan Choi (최준환)]

> On Fri, Dec 6, 2013 at 2:52 PM, Geoffrey So <gsiisg at gmail.com> wrote:
>> I believe you can access rectangular sub volume of the data with something
>> like
>>
>> sv = pf.h.region([0.5]*3, [0.21, .21, .72], [.28, .28, .79])
>>
>> Shown here when running halo finder on a sub volume
>> http://yt-project.org/docs/2.6/analyzing/analysis_modules/running_halofinder.html?highlight=sub%20region
>>
>> And you can use other 3D objects like spheres, ellipsoids etc, for a thin
>> slice of the data you can make your rectangular region small in one of the
>> dimension.
>>
>> When making plots just pass in the sv 3D sub volume object instead of the
>> usual pf for plotting the entire simulation.
>
> This will work if the Octree is parsed on demand; what I think Junhwan
> is running into right now is that the entire octree is loaded at
> startup.  So you end up with a memory constant that gets added on for
> each process; this will reduce the *additional* overhead of loading
> data, but he still has memory for each leaf node of the oct.
>
Do you mean that there is no way to read 4098^3 Ramses data using yt?
I tried to define small region of the simulation and make a density
projection plot, but it looks fail owing to the same reason.
Is there way to temporally get around this problem?

Thank you for continuous help,
Junhwan