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Posted to user@mahout.apache.org by Zhou Jiang <jz...@gmail.com> on 2015/08/19 04:42:36 UTC

Is it possible to use Mahout Random Forests work with image(pixel) data in libsvm format?

Hi All,

The Default Random Forests MapReduce works with UCI glass data. 

ID f1 f2 f3 … fn L

Is there a way to make it work with image data in libsvm format(Sparse Representation) listed as blow:

L index1:feature1 index2:feature2 … indexk:featurek


Thanks

Re: Is it possible to use Mahout Random Forests work with image(pixel) data in libsvm format?

Posted by Zhou Jiang <jz...@gmail.com>.

Thank you for your reply. But the data is very sparse and reformat the input file means add a lot of zero, which will affect the performance.
To me, it’s better to stick to the sparse representation.

> On Aug 18, 2015, at 10:15 PM, Ted Dunning <te...@gmail.com> wrote:
> 
> Seems like a simple format translation.
> 
> Why not just reformat the input file?
> 
> 
> 
> On Tue, Aug 18, 2015 at 7:42 PM, Zhou Jiang <jz...@gmail.com> wrote:
> 
>> Hi All,
>> 
>> The Default Random Forests MapReduce works with UCI glass data.
>> 
>> ID f1 f2 f3 … fn L
>> 
>> Is there a way to make it work with image data in libsvm format(Sparse
>> Representation) listed as blow:
>> 
>> L index1:feature1 index2:feature2 … indexk:featurek
>> 
>> 
>> Thanks
>> 
>>

Re: Is it possible to use Mahout Random Forests work with image(pixel) data in libsvm format?

Posted by Ted Dunning <te...@gmail.com>.

Seems like a simple format translation.

Why not just reformat the input file?

On Tue, Aug 18, 2015 at 7:42 PM, Zhou Jiang <jz...@gmail.com> wrote:

> Hi All,
>
> The Default Random Forests MapReduce works with UCI glass data.
>
> ID f1 f2 f3 … fn L
>
> Is there a way to make it work with image data in libsvm format(Sparse
> Representation) listed as blow:
>
> L index1:feature1 index2:feature2 … indexk:featurek
>
>
> Thanks
>
>