[GRASS5] i.pca and masks

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I did some PCA on images using different masks and only then I noticed
that in the end I got the full image, without a mask. However in the man
page it says:

The current geographic region definition and mask settings are respected
when reading the input raster map layers

What does this mean? That it uses the mask only for making the pca
calculations, but then shows up the whole image?
If I would want to build up a image on the mask area (hard disk
space...), would it be possible?

Thanks,

- --
Gualter Barbas Baptista
gualter@gaia.org.pt ICQ# 8106393 jabber.org: gandhiano

GAIA - Grupo de Acção e Intervenção Ambiental
gaia@gaia.org.pt
Portugal
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I should further add that the i.pca on the different masks (and without
mask) looks exactly the same, so I don't really think he's using the
mask for the input.

Gualter Barbas Baptista wrote:

| I did some PCA on images using different masks and only then I noticed
| that in the end I got the full image, without a mask. However in the man
| page it says:
|
| The current geographic region definition and mask settings are respected
| when reading the input raster map layers
|
| What does this mean? That it uses the mask only for making the pca
| calculations, but then shows up the whole image?
| If I would want to build up a image on the mask area (hard disk
| space...), would it be possible?
|
| Thanks,
|
| --
| Gualter Barbas Baptista
| gualter@gaia.org.pt ICQ# 8106393 jabber.org: gandhiano
|
| GAIA - Grupo de Acção e Intervenção Ambiental
| gaia@gaia.org.pt
| Portugal

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http://grass.itc.it/mailman/listinfo/grass5

- --
Gualter Barbas Baptista
gualter@gaia.org.pt ICQ# 8106393 jabber.org: gandhiano

GAIA - Grupo de Acção e Intervenção Ambiental
gaia@gaia.org.pt
Portugal

- --
Gualter Barbas Baptista
gualter@gaia.org.pt ICQ# 8106393 jabber.org: gandhiano

GAIA - Grupo de Acção e Intervenção Ambiental
gaia@gaia.org.pt
Portugal
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Gualter Barbas Baptista wrote:

I did some PCA on images using different masks and only then I noticed
that in the end I got the full image, without a mask. However in the man
page it says:

The current geographic region definition and mask settings are respected
when reading the input raster map layers

What does this mean? That it uses the mask only for making the pca
calculations, but then shows up the whole image?
If I would want to build up a image on the mask area (hard disk
space...), would it be possible?

It's a bug in one of the core functions, G_get_map_row(), which is
used for reading maps. This function is supposed to automatically take
account of the mask, but it doesn't; in reality this function is
identical to G_get_map_row_nomask().

The net result is that any module which uses G_get_map_row() rather
than G_get_raster_row() etc will completely ignore the mask.

Note: this bug is present in the earliest CVS version, dating back to
1999/12/29. It isn't present in 4.3; between 4.3 and the earliest CVS
version, src/libes/gis/get_row.c was completely rewritten to handle
floating-point and null values.

If you built GRASS from source code, apply the attached patch and
recompile. Otherwise, wait for 5.0.1.

--
Glynn Clements <glynn.clements@virgin.net>

(attachments)

grass-nomask.patch (647 Bytes)

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|If you built GRASS from source code

I didn't, but I would like to do it now. However, I don't find the source code for 5.0.0, only for the pre5. Is there any branch on CVS for getting the final release of 5.0.0?

Thanks,

- --
Gualter Barbas Baptista
gualter@gaia.org.pt ICQ# 8106393 jabber.org: gandhiano

GAIA - Grupo de Acção e Intervenção Ambiental
gaia@gaia.org.pt
Portugal
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This is it. I noticed that the accompanying text still says preX,
that needs to be removed.

Helena

http://grass.itc.it/grass5/source/

Gualter Barbas Baptista wrote:

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|If you built GRASS from source code

I didn't, but I would like to do it now. However, I don't find the
source code for 5.0.0, only for the pre5. Is there any branch on CVS for
getting the final release of 5.0.0?

Thanks,

- --
Gualter Barbas Baptista
gualter@gaia.org.pt ICQ# 8106393 jabber.org: gandhiano

GAIA - Grupo de Acção e Intervenção Ambiental
gaia@gaia.org.pt
Portugal
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_______________________________________________
grass5 mailing list
grass5@grass.itc.it
http://grass.itc.it/mailman/listinfo/grass5

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On Sat, 21 Sep 2002 12:56:51 +0100, Gualter Barbas Baptista <gualter@netcabo.pt> wrote:

|If you built GRASS from source code

I didn't, but I would like to do it now. However, I don't find the
source code for 5.0.0, only for the pre5. Is there any branch on CVS
for getting the final release of 5.0.0?

http://grass.itc.it/grass5/source/

Moritz
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On Sat, 21 Sep 2002 07:22:41 -0400, Helena <hmitaso@unity.ncsu.edu> wrote:

This is it. I noticed that the accompanying text still says preX,
that needs to be removed.

done

Moritz
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Gualter Barbas Baptista wrote:

|If you built GRASS from source code

I didn't, but I would like to do it now. However, I don't find the
source code for 5.0.0, only for the pre5. Is there any branch on CVS for
getting the final release of 5.0.0?

The 5.0.0 release has the (non-branch) tag:

  release_30_08_2002_grass5_0_0

--
Glynn Clements <glynn.clements@virgin.net>

On Sat, Sep 21, 2002 at 10:48:30PM +0100, Glynn Clements wrote:

Gualter Barbas Baptista wrote:

> |If you built GRASS from source code
>
> I didn't, but I would like to do it now. However, I don't find the
> source code for 5.0.0, only for the pre5. Is there any branch on CVS for
> getting the final release of 5.0.0?

The 5.0.0 release has the (non-branch) tag:

  release_30_08_2002_grass5_0_0

I have updated the CVS tags page:
http://grass.itc.it/grasscvstags.html

Hopefully it is a bit better now. Let me know if not.

Markus