Re: [igraph] reading large, sparse graph with read.graph

[Gábor Csárdi]

On Wed, Apr 28, 2010 at 10:29 AM, Gábor Csárdi <address@hidden> wrote:
> On Wed, Apr 28, 2010 at 12:42 AM, David Hunkins <address@hidden> wrote:
>> So I am trying both of your suggestions (thanks):
>>
>> Tamas: I created a test file that's a subset of the very large file I'm
>> working with. I had already converted it to Pajek format. The read.graph
>> function reads it into memory in about 15 seconds. But it is taking a very
>> long time to write out the lgl file (now thirty minutes already). The memory
>> footprint doesn't change, and the cpu is maxed at 100%. I would think that
>> the more 'compact' format could be written out quite fast, so I think
>> something is wrong.
>
> You are right, this is very slow if you have edge weights. I am not
> sure why, we just call back to R to convert the numbers to strings and
> then print them, but the conversion is very slow. I'll check this.

OK, I checked this, it was a stupid error of mine, the conversion
function was called a lot of times. I corrected it, you can download a
fixed version of a source R package from here:
http://code.google.com/p/igraph/downloads/list

Best,
Gabor

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-- 
Gabor Csardi <address@hidden>     UNIL DGM