compare several maps

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Carlos Grohmann-2

compare several maps

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What do you guys think is a good approach to compare several raster
maps at the same time? correlation matrix? some graphical output?
density plots?

cheers

carlos

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+-----------------------------------------------------------+
              Carlos Henrique Grohmann - Guano
  Visiting Researcher at Kingston University London - UK
  Geologist M.Sc  - Doctorate Student at IGc-USP - Brazil
Linux User #89721  - carlos dot grohmann at gmail dot com
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Jarosław Jasiewicz

Re: compare several maps

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Carlos "Guâno" Grohmann wrote:
> What do you guys think is a good approach to compare several raster
> maps at the same time? correlation matrix? some graphical output?
> density plots?
>
> cheers
>
> carlos
>
>  
well, give us more detail what do you need

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Carlos Grohmann-2

Re: compare several maps

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Sure, sorry about that.

I am analyzing various methods of calculation of surface roughness. So
I will have several maps, produced with different methods, at
different scales and with different datasets.
All maps are calculated with moving-window procedures. I'll have maps
calculated  with neighborhoods of 3,5,7,9,11,.. pixels, over DEMs with
5,10,25,50,90 meters resolution, using probably three different
methods.

So I'll end up with tens of maps! I was wondering what would be a good
approach to compare them. I was thinking to rescale all maps to a
common range (say, 0-255) first, and then compare.

I guess it makes sense to compare like this:

DEM_10m - Window_Size_3x3 - method A/B/C
DEM_10m - Window_Size_5x5 - method A/B/C

and so on for each dem resolution and window size.

carlos


On 8/7/07, Jarek Jasiewicz <[hidden email]> wrote:

> Carlos "Guâno" Grohmann wrote:
> > What do you guys think is a good approach to compare several raster
> > maps at the same time? correlation matrix? some graphical output?
> > density plots?
> >
> > cheers
> >
> > carlos
> >
> >
> well, give us more detail what do you need
>


--
+-----------------------------------------------------------+
              Carlos Henrique Grohmann - Guano
  Visiting Researcher at Kingston University London - UK
  Geologist M.Sc  - Doctorate Student at IGc-USP - Brazil
Linux User #89721  - carlos dot grohmann at gmail dot com
+-----------------------------------------------------------+
_________________
"Good morning, doctors. I have taken the liberty of removing Windows
95 from my hard drive."
--The winning entry in a "What were HAL's first words" contest judged
by 2001: A SPACE ODYSSEY creator Arthur C. Clarke

Can't stop the signal.

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Carlos Grohmann-2

Re: compare several maps

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In reply to this post by Carlos Grohmann-2
Thanks for the paper, William. Sounds very interesting.

Carlos



On 8/8/07, William Hargrove <[hidden email]> wrote:

> Carlos:
>
> Have a look at our Mapcurves method:
> http://research.esd.ornl.gov/~hnw/MapCurvesPaper_JGS2006.pdf
>
> Hope this helps,
>
> Bill H.
>
> Carlos "Guâno" Grohmann wrote:
>
> >What do you guys think is a good approach to compare several raster
> >maps at the same time? correlation matrix? some graphical output?
> >density plots?
> >
> >cheers
> >
> >carlos
> >
> >
> >
>
>
> --
> William W. Hargrove
> Eastern Forest Threat Assessment Center
> USDA Forest Service
> Southern Research Station
> 200 WT Weaver Boulevard
> Asheville, NC  28804-3454
>
> working remotely at:
>
> Computer Science & Mathematics Division
> Oak Ridge National Laboratory
> P.O. Box 2008, M.S. 6016
> Building 5600, Room I322
> Oak Ridge, TN  37831-6016
> (865) 241-2748
> (865) 235-4753 (cell)
> (865) 576-5491 (fax)
> [hidden email]
> http://www.geobabble.org/~hnw
> FedEx/UPS, use "Bethel Valley Rd."
>
>


--
+-----------------------------------------------------------+
              Carlos Henrique Grohmann - Guano
  Visiting Researcher at Kingston University London - UK
  Geologist M.Sc  - Doctorate Student at IGc-USP - Brazil
Linux User #89721  - carlos dot grohmann at gmail dot com
+-----------------------------------------------------------+
_________________
"Good morning, doctors. I have taken the liberty of removing Windows
95 from my hard drive."
--The winning entry in a "What were HAL's first words" contest judged
by 2001: A SPACE ODYSSEY creator Arthur C. Clarke

Can't stop the signal.

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[hidden email]
http://grass.itc.it/mailman/listinfo/statsgrass
Jarosław Jasiewicz

Re: compare several maps

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In reply to this post by Carlos Grohmann-2
Carlos "Guâno" Grohmann wrote:

> Sure, sorry about that.
>
> I am analyzing various methods of calculation of surface roughness. So
> I will have several maps, produced with different methods, at
> different scales and with different datasets.
> All maps are calculated with moving-window procedures. I'll have maps
> calculated  with neighborhoods of 3,5,7,9,11,.. pixels, over DEMs with
> 5,10,25,50,90 meters resolution, using probably three different
> methods.
>
> So I'll end up with tens of maps! I was wondering what would be a good
> approach to compare them. I was thinking to rescale all maps to a
> common range (say, 0-255) first, and then compare.
>
> I guess it makes sense to compare like this:
>
> DEM_10m - Window_Size_3x3 - method A/B/C
> DEM_10m - Window_Size_5x5 - method A/B/C
>
> and so on for each dem resolution and window size.
>
> carlos
>
>
> On 8/7/07, Jarek Jasiewicz <[hidden email]> wrote:
>  
>> Carlos "Guâno" Grohmann wrote:
>>    
>>> What do you guys think is a good approach to compare several raster
>>> maps at the same time? correlation matrix? some graphical output?
>>> density plots?
>>>
>>> cheers
>>>
>>> carlos
>>>
>>>
>>>      
>> well, give us more detail what do you need
>>
>>    
>
>
>  
difficult question, correlation matrix seems not to be good method, if
you want to compare data produced with different resolution and
different moving window (i.e pixel with greater area will have in all
paces teh same value will cover  group of small pixels with compleatly
deferent walue)

maybe autocorellation in individual map will  be  interesting parameter
density plots also seems interesting

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