On Thu, Nov 26, 2015 at 10:34 PM, Uttam Kumar wrote:
> As I understand GRASS can handle both conditions (i.e. the number of
> clusters (through the parameter classes) and "iterations" as the criteria to
> converge. The algorithm will stop as soon as any of the conditions are met
> first.
>
> https
As I understand GRASS can handle both conditions (i.e. the number of
clusters (through the parameter classes) and "iterations" as the criteria
to converge. The algorithm will stop as soon as any of the conditions are
met first.
https://grass.osgeo.org/grass64/manuals/i.cluster.html
On Thu, Nov 26
As a followup, it looks like changing the minimum cluster size may reduce the
number of final clusters, but the final number seem not to exceed the initial
number.
Michael
C. Michael Barton
Director, Center for Social Dynamics & Complexity
Professor of Anthropology, School o
I'm trying out GRASS's unsupervised classification functions. As I understand
it, it is a 2 step process.
1. run i.cluster to get cluster signatures
2. run i.maxlik using the cluster signatures to generate the spatial clusters
I've varied the parameters several times, and AFAICT, setting the ini
On 19/08/11 06:56, Gaspar Reyes Póndigo wrote:
Hi, Dear users
I have one question:
What is the name of the method of i.cluster?
Isodata, Isocluster or K-means?
As number of clusters can change, I would say isodata. I don't know if
isocluster is a different algorithm, or just the name given
Hi, Dear users
I have one question:
What is the name of the method of i.cluster?
Isodata, Isocluster or K-means?
Gaspar Reyes Póndigo
Universidad del Mar, Oaxaca, México
Campus Puerto-Ángel
Carretera principal Puerto Ángel Zipolite km 1.5
C.P. 70902
___
Nick and Daniel,
Thanks for the suggestions. I did manage to get it to run after playing
with some of the variables. If I used the default values for "sample"
and "min_size" it worked. Unfortunately the default values are less than
ideal. I think the main problem is with the "sample" parameter
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,
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
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 signat
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
Dominik Wiedner wrote:
When I want to execute i.maxlik, the output reads, that the file with the
signatures can't be read.
Now I'm lost and can only ask stupid questions: Can you read the
signature file with a standard text editor and do the contents make
sense? No offence, but did you spec
Markus Metz-2 wrote:
>
>
> This is a request for more than 7GB of memory, unlikely that this is
> needed for a Landsat scene. Do the current region settings match the
> raster to be processed?
>
>
Hi Markus,
This problem is solved, but another appears!
When I want to execute i.maxlik, t
Dominik Wiedner wrote:
Hi Folks,
Once again, I got some problems with the windows version of GRASS.
When I want to do an unsupervised classification, the output of i.cluster
reads:
"G_calloc: unable to allocate 11 * 8 bytes at alloc_cell.c:128"
This is a request for more than 7GB
Hi Folks,
Once again, I got some problems with the windows version of GRASS.
When I want to do an unsupervised classification, the output of i.cluster
reads:
"G_calloc: unable to allocate 11 * 8 bytes at alloc_cell.c:128"
The command I entered reads as follows:
i.cluster group=lands..
Dylan Beaudette wrote:
On Thu, Jan 1, 2009 at 10:57 AM, Micha Silver wrote:
One set of aerial photos are from the 1950's -1960's. These are all black
and white photos: single band tiff. The newer set of aerial photos are
color images from 2005-2007.
The region is a "savanna" area with spa
On Thu, Jan 1, 2009 at 10:57 AM, Micha Silver wrote:
>
> One set of aerial photos are from the 1950's -1960's. These are all black
> and white photos: single band tiff. The newer set of aerial photos are
> color images from 2005-2007.
> The region is a "savanna" area with sparse trees and bushes
Markus Neteler wrote:
On Thu, Jan 1, 2009 at 4:06 PM, Micha Silver wrote:
Happy New Year to all!
Happy New Year!
I want to run some r.le analyses on rasters I will create from two
[please consider r.li which way faster]
Thanks for the tip.
ortho-photo images. The n
On Thu, Jan 1, 2009 at 4:06 PM, Micha Silver wrote:
> Happy New Year to all!
Happy New Year!
> I want to run some r.le analyses on rasters I will create from two
[please consider r.li which way faster]
> ortho-photo images. The newer ortho-photo is full color, so when importing
> into GRASS I
Happy New Year to all!
I want to run some r.le analyses on rasters I will create from two
ortho-photo images. The newer ortho-photo is full color, so when
importing into GRASS I get the three RGB bands. So I make an image group
and subgroup with the three bands and I can do the clustering. H
Raphael Saldanha wrote:
> I'm trying to run i.cluster, with WinGRASS 6.3.
>
> The command: *i.cluster [EMAIL PROTECTED] subgroup=cena1 sigfile=sig
> classes=5 iterations=30 convergence=98.0 separation=0.0 min_size=17 *
>
> But I'm having this error: *No such file or directory*
>
> And, if I tr
Hi!
I'm trying to run i.cluster, with WinGRASS 6.3.
The command: *i.cluster [EMAIL PROTECTED] subgroup=cena1 sigfile=sig
classes=5 iterations=30 convergence=98.0 separation=0.0 min_size=17 *
But I'm having this error: *No such file or directory*
And, if I try some directory, like *i.cluster
[EM
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