The ciftiopen option of matlab cifti support should allow you to load the
file, though I think it loads as double, and you'd need to convert it to
single to reclaim some memory (which comes close to your memory+swap cap,
as it needs the double and single versions allocated simultaneously in
order to do the conversion).

One possibility, if you don't really need a 90k x 90k network, is
downsampling or parcellating the dense connectome, see
http://www.humanconnectome.org/software/workbench-command.php?function=-cifti-parcellate
.

If you do need the 90k x 90k resolution, and can work in c++ instead of
matlab, you could use CiftiLib for reading the file (can read single rows
from disk, rather than the entire matrix into memory), or code up a new
command for wb_command (same support for cifti, but also support for other
file types, access to other algorithms).

Tim


On Tue, Oct 25, 2016 at 3:21 PM, Harms, Michael <[email protected]> wrote:

>
> If you’re talking about some sort of community/modularity analysis, then,
> no, there aren’t any tools for doing that directly in workbench.
>
> Maybe Tim C. will have some suggestions.  I believe that the dconn is
> stored as a single precision float.  Have you tried using ‘ciftiopen’?  I’m
> not sure if that preserves the single precision format of the data, or if
> it balloons by a factor of 2 due to conversion to matlab’s default double
> precision format.  If you can keep it as single precision in matlab, you
> might be able to work with it provided Matlab has access to a lot of RAM.
>
> cheers,
> -MH
>
> --
> Michael Harms, Ph.D.
> -----------------------------------------------------------
> Conte Center for the Neuroscience of Mental Disorders
> Washington University School of Medicine
> Department of Psychiatry, Box 8134
> 660 South Euclid Ave. Tel: 314-747-6173
> St. Louis, MO  63110 Email: [email protected]
>
> From: "GLOMB, KATHARINA" <[email protected]>
> Date: Tuesday, October 25, 2016 at 10:35 AM
> To: Michael Harms <[email protected]>
> Subject: Re: [HCP-Users] Problem with handling dense FC matrix
>
> Hi Michael,
>
> wow, thank you for this lightning speed reply! I want to run some network
> analysis on this matrix.I don't need the whole matrix, I would just need
> the unique entries (off-diagonal upper or lower triangular, squareform() in
> Matlab) - maybe that would help? Can workbench help me in any way to do
> this?
>
> Or do you have any other ideas?
>
> Thank you!
> Katharina
>
> On Tue, Oct 25, 2016 at 5:21 PM, Harms, Michael <[email protected]> wrote:
>
>>
>> What are you trying to do with the file in workbench?  Have you reviewed
>> the tutorial, because it includes examples (and a scene to help you along)
>> of using that file.
>>
>> Trying to load/work with that file in matlab is probably going to cause
>> loads of pain.  It is just too large to load the entire thing into matlab.
>>
>> cheers,
>> -MH
>>
>> --
>> Michael Harms, Ph.D.
>> -----------------------------------------------------------
>> Conte Center for the Neuroscience of Mental Disorders
>> Washington University School of Medicine
>> Department of Psychiatry, Box 8134
>> 660 South Euclid Ave.Tel: 314-747-6173
>> St. Louis, MO  63110Email: [email protected]
>>
>> From: <[email protected]> on behalf of "GLOMB,
>> KATHARINA" <[email protected]>
>> Date: Tuesday, October 25, 2016 at 10:15 AM
>> To: "[email protected]" <[email protected]>
>> Subject: [HCP-Users] Problem with handling dense FC matrix
>>
>> Hello HCP users,
>>
>> I am new to HCP so please excuse me if I'm asking something that should
>> be obvious. I've tried to find a solution but haven't been successful so
>> far. I am trying to use the file 
>> HCP_S900_820_rfMRI_MSMAll_groupPCA_d4500ROW_zcorr.dconn.nii
>> which to my understanding should contain a full FC matrix that is an
>> average of 820 subjects. I want to feed this matrix into a Matlab function.
>> Of course, this is problematic because of the memory requirements. I have
>> tried to read the file using ft_read_cifti from fieldtrip, but Matlab
>> crashes at 112 GB of memory. So clearly, this is not the way.
>>
>> I know I am supposed to be able to use workbench for that, but can't make
>> it work so far. Can someone point me in the right direction? Is what I'm
>> trying to do impossible?
>>
>> I am using a cluster that can handle up to 132 GB of memory per cpu
>> (RAM+swap) and runs Debian.
>>
>> Thank you!!
>> Katharina
>>
>> --
>> PhD candidate <http://www.cns.upf.edu/katharina>
>> Computational Neuroscience Group <http://www.cns.upf.edu/>
>> Center for Brain and Cognition <http://cbc.upf.edu/>
>> Universitat Pompeu Fabra <http://www.upf.edu/>
>> Barcelona, Spain
>>
>> I am funded by the INDIREA <http://www.indirea.eu/> Marie Curie Initial
>> Training Network.
>>
>> _______________________________________________
>> HCP-Users mailing list
>> [email protected]
>> http://lists.humanconnectome.org/mailman/listinfo/hcp-users
>>
>>
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>> The materials in this message are private and may contain Protected
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>
>
>
> --
> PhD candidate <http://www.cns.upf.edu/katharina>
> Computational Neuroscience Group <http://www.cns.upf.edu/>
> Center for Brain and Cognition <http://cbc.upf.edu/>
> Universitat Pompeu Fabra <http://www.upf.edu/>
> Barcelona, Spain
>
> I am funded by the INDIREA <http://www.indirea.eu/> Marie Curie Initial
> Training Network.
>
>
> ------------------------------
>
> The materials in this message are private and may contain Protected
> Healthcare Information or other information of a sensitive nature. If you
> are not the intended recipient, be advised that any unauthorized use,
> disclosure, copying or the taking of any action in reliance on the contents
> of this information is strictly prohibited. If you have received this email
> in error, please immediately notify the sender via telephone or return mail.
>
> _______________________________________________
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