[GRASS-user] i.cluster not working in GRASS 7

[Nick Jachowski]

Also, make sure you mask any Nulls since that often seems to be the problem when i.cluster doesn't work as expected, especially if you are using landsat 7 slc-off imagery - although I've also experienced it with Landsat 4 and 5 imagery. 

[Sent from a mobile device]

On Feb 18, 2011, at 4:38 PM, Nick Jachowski <njachowski at gmail.com> wrote:

> Hi Ned and Daniel,
> 
> I have run into this problem in the past, and I believe it may have to do with your convergence, min_size, and classes settings.  Try decreasing some of those and see if you don't get better results.  You can also try increasing your separation from 0.0 (the default) to 1.0 or 1.5.
> 
> Nick
> 
> On Fri, Feb 18, 2011 at 4:24 PM, daniel mcinerney <daniel.o.mcinerney at gmail.com> wrote:
> Hi Ned,
> 
> I have been using i.cluster in GRASS 7 on a 64-bit fedora server,
> without any trouble.  However, I managed to replicate your problem
> and create a single class output by setting the parameter
> 'sample=5,5' as you had done in your example. If I run i.cluster without
> that parameter, the signature file and classification output both 
> have the number of predefined classes. 
> 
> Can you see if this helps with your data?
> 
> Regards,
> Daniel.
> 
> 
> On Thu, Feb 17, 2011 at 7:49 PM, Ned Horning <horning at amnh.org> wrote:
> Hi - I would like to do an unsupervised classification using i.cluster from GRASS 7 on my Ubuntu 64-bit machine. When I run i.cluster then i.maxlik on a Landsat image I only get one output class, the entire image. Only one class appears in the signature file so the problem is with the i.cluster step. I tried running i.cluster on different images and always get just one class.
> 
> Here is the command line I'm using:
> i.cluster group=TM_r15c33 at PERMANENT subgroup=AllBands signaturefile=IsoDataSigs2 classes=20 sample=5,5 convergence=99.9 min_size=10000
> 
> Is anyone able to get i.cluster to work properly? It would be helpful to know if it's a user problem or a bug.
> 
> Thanks in advance to anyone who can help.
> 
> All the best,
> 
> Ned
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