[Networkit] Reading graph segfaults

Lars Beckmann lars.beckmann at gmail.com
Thu Apr 24 16:18:40 CEST 2014


Hi Christian,

thanks for the info! I pulled from the repo and updated to the dev branch.
I then built the core, which worked without errors. When I then tried to do
"from NetworKit import *", I get this error message:

Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/adminuser/Utilities/NetworKit/src/python/NetworKit.py", line
24, in <module> import centrality
File "/home/adminuser/Utilities/NetworKit/src/python/centrality.py", line
1, in <module> from _NetworKit import Betweenness, PageRank,
EigenvectorCentrality, DegreeCentrality, ApproxBetweenness
ImportError: cannot import name PageRank

When I switched back to the default branch, rebuilt and ran the statement
again, I got no errors. But ApproxBetweenness is only in the Dev branch as
far as I could see. I am not a Python expert, so maybe there is an obvious
solution to only import ApproxBetweenness. For now I would be happy to test
that part (PageRank is interesting too, but maybe later). Or are we doing
something completely wrong here?

Best,

Lars


On Tue, Apr 22, 2014 at 1:24 PM, Staudt, Christian (ITI) <
christian.staudt at kit.edu> wrote:

> Hi Lars,
> in addition to the paper mentioned by Henning (
> http://arxiv.org/abs/1403.3005), there a two main sources  for
> documentation on NetworKit’s classes and functions:
>
> a) the user guide in the form of an IPython Notebook:
> Doc/Notebooks/NetworKit_UserGuide.ipynb
> b) the Python docstrings for classes and functions, as well as Doxygen
> comments in the C++ source code
>
> I admit that both sources are not in perfect shape, so please inform us if
> and maybe how they could be improved.
>
> Especially for centrality.ApproxBetweenness, which is a very recent
> addition, we are interested in your practical experiences, e.g. Did it work
> for your data? How long did it take? Which parameters did you chose for
> your purposes? etc.
>
> Kind regards
> Christian
>
> christian.staudt at kit.edu
> http://parco.iti.kit.edu/staudt/index-en.shtml
> Institut of Theoretical Computer Science - Parallel Computing Group
> Building 50.34 Room 249
> Karlsruhe Institute of Technology (KIT)
>
>
>
>
>
> Am 22.04.2014 um 12:54 schrieb Lars Beckmann <lars.beckmann at gmail.com>:
>
> Hi Henning,
>
> thanks for the quick reply, that fixed the issue.
>
> Christian said that there is an approximation algorithm for betweenness
> centrality in the dev-branch. Is there an overview for all the available
> algorithms and their usage? In particular we are interested in centrality
> measures for very large graphs (millions of nodes, (hundreds of) millions
> of edges). If you could point me to docs or any other resource that shows
> the usage of these algorithms, that would be great. Note: I did go trough
> the doc folder in the repo, but maybe there is more that I haven't found
> yet?
>
> Thanks in advance,
>
> Lars
>
>
> On Fri, Apr 18, 2014 at 5:49 PM, Henning Meyerhenke <meyerhenke at kit.edu>wrote:
>
>> Dear Lars,
>>
>> Thanks for your request. The reason for the error is the input graph's
>> slight, yet important deviation from the input format requirements. The
>> Metis format requires graphs to be 1-indexed, i.e. vertex indices start
>> with 1, not 0.
>>
>> The unfulfilled assertion happens when an edge with index 0 occurs. Then
>> NetworKit's range check fails.
>>
>> Could you please change your data set according to the format and try
>> again?
>>
>> Thanks,
>> Henning
>>
>>
>> Am 18.04.14 15:03, schrieb Lars Beckmann:
>>
>>  Hi,
>>>
>>> we are trying to use NetworKit to compute centrality measures, but
>>> NetworKit segfaults when we try to read the graph. We are using a clean
>>> VM with Ubuntu 13.10
>>> (http://virtualboximages.com/Ubuntu+13.10+amd64+VirtualBox+
>>> VDI+Virtual+Appliance)
>>> where we installed the prerequisites mentioned in the NetworKit readme.
>>> We successfully built NetworKit on the VM, but when we try to read our
>>> graph using: G = graphio.METISGraphReader().read("xxx.graph") NetworKit
>>> segfaults. We have built NetworKit without debug flags, but we can do
>>> so, if that is important for the devs to help us out.
>>>
>>> You can find the graph in question here:
>>> https://drive.google.com/file/d/0B7vRIovbLojkSHpTUy1hR3dFRHM/
>>> edit?usp=sharing
>>>
>>> Thanks for your help,
>>>
>>> Lars
>>>
>>> --
>>> Lars Beckmann
>>>
>>> Uhlenstraße 10
>>> 33098 Paderborn
>>> Germany
>>>
>>> Cell (D2): +49 (0) 178 59 69 150
>>> Phone: +49 (0) 89 380 123 90
>>> Fax: +49 (0) 180 102 113 4628
>>>
>>
>> --
>>
>> =======================================================
>> Karlsruhe Institute of Technology (KIT)
>> Institute of Theoretical Informatics (ITI)
>>
>> Juniorprof. Dr. Henning Meyerhenke
>> Theoret. Informatics / Parallel Computing
>>
>> Phone: +49-721-608-41876
>> Web: http://parco.iti.kit.edu/henningm/
>>
>> KIT - University of the State of Baden-Wuerttemberg and
>> National Research Center of the Helmholtz Association
>> =======================================================
>>
>>
>
>
> --
> Lars Beckmann
>
> Uhlenstraße 10
> 33098 Paderborn
> Germany
>
> Cell (D2): +49 (0) 178 59 69 150
> Phone: +49 (0) 89 380 123 90
> Fax: +49 (0) 180 102 113 4628
>  <ATT00001.c>
>
>
>
> _______________________________________________
> NetworKit mailing list
> NetworKit at ira.uni-karlsruhe.de
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>
>


-- 
Lars Beckmann

Uhlenstraße 10
33098 Paderborn
Germany

Cell (D2): +49 (0) 178 59 69 150
Phone: +49 (0) 89 380 123 90
Fax: +49 (0) 180 102 113 4628
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