[GRASS5] i.tm.dehaze problem

GRASS GRASS developer
1

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Hi,

I'm trying to run the i.tm.dehaze but I'm getting the errors below. Does anyone know what this means and how can be solved? I'm running 5.0.0pre3, could this be some old bug?

GRASS:~ > i.tm.dehaze inverno.tasscap.4 b1 b2 b3 b4 b5 b7
r.stats: 100%
1 variables
0 observations
ERROR: SVDCMP: You must augment A with extra zero rows
Result for channel b1: sl: i:

r.stats: 100%
1 variables
0 observations
ERROR: SVDCMP: You must augment A with extra zero rows
Result for channel b2: i:

r.stats: 100%
1 variables
0 observations
ERROR: SVDCMP: You must augment A with extra zero rows
Result for channel b3: i:

r.stats: 100%
1 variables
0 observations
ERROR: SVDCMP: You must augment A with extra zero rows
Result for channel b4: i:

r.stats: 100%
1 variables
0 observations
ERROR: SVDCMP: You must augment A with extra zero rows
Result for channel b5: i:

Running the dehaze formula: tm.dehaze = tm - [ (tass4 - tm_i) * tm_s]
~ with internally calculated i:intercept, s: slope
you have confused me
b1.dehaze: raster map not found
you have confused me
b2.dehaze: raster map not found
you have confused me
b3.dehaze: raster map not found
you have confused me
b4.dehaze: raster map not found
you have confused me
b5.dehaze: raster map not found

The new dehazed bands are:
b1.dehaze, b2.dehaze, b3.dehaze, b4.dehaze, b5.dehaze

Consider to run r.colors or i.grey.scale to get a grey color table

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

GAIA - Grupo de Acção e Intervenção Ambiental
ae-gaia@students.fct.unl.pt
Portugal
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2

On Sat, Aug 10, 2002 at 07:21:14PM +0100, Gualter Barbas Baptista wrote:

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Hi,

I'm trying to run the i.tm.dehaze but I'm getting the errors below. Does
anyone know what this means and how can be solved? I'm running
5.0.0pre3, could this be some old bug?

GRASS:~ > i.tm.dehaze inverno.tasscap.4 b1 b2 b3 b4 b5 b7
r.stats: 100%
1 variables
0 observations
ERROR: SVDCMP: You must augment A with extra zero rows

Hi,

this looks as a problem r.linear.regression. It is suspicious that
there are '0 observations'.

Are you sure that you work in a region with data (check with d.erase;d.rast)?

Note that i.tm.dehaze is a script without good error testing.

Markus

3

On Mon, Aug 12, 2002 at 04:48:09PM +0200, Markus Neteler wrote:

On Sat, Aug 10, 2002 at 07:21:14PM +0100, Gualter Barbas Baptista wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Hi,
>
> I'm trying to run the i.tm.dehaze but I'm getting the errors below. Does
> anyone know what this means and how can be solved? I'm running
> 5.0.0pre3, could this be some old bug?
>
> GRASS:~ > i.tm.dehaze inverno.tasscap.4 b1 b2 b3 b4 b5 b7
> r.stats: 100%
> 1 variables
> 0 observations
> ERROR: SVDCMP: You must augment A with extra zero rows

Hi,

this looks as a problem r.linear.regression. It is suspicious that
there are '0 observations'.

Are you sure that you work in a region with data (check with d.erase;d.rast)?

Note that i.tm.dehaze is a script without good error testing.

Ok, I have submitted a simple error test which stop the script
when r.linear.regression stops due to erratic input.

Try i.tm.dehaze with a smaller region first. The input size is
somewhat limited according to the machine's resources where GRASS
is running on.

With my TM data it runs well.

Markus

4

On Mon, Aug 12, 2002 at 11:03:06PM +0100, Gualter Barbas Baptista wrote:
[...]

|>>GRASS:~ > i.tm.dehaze inverno.tasscap.4 b1 b2 b3 b4 b5 b7
|>>r.stats: 100%
|>>1 variables
|>>0 observations
|>>ERROR: SVDCMP: You must augment A with extra zero rows

[...]

Ok, I'll try with a smaller region. Anyway, I didn't notice a resource
exhaustion on my computer while I was running i.tm.dehaze.

Well, the modules called by i.tm.dehaze are partly very old and
do not crash elegant :slight_smile: The message above is from r.linear.regression.

|With my TM data it runs well.
But only with a smaller region or with the whole image?

It should be sufficient to zoom a, say 500x500 region and run it
again (since GRASS raster is region sensitive).

Let me know,

Markus

5

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Markus Neteler wrote:

|On Mon, Aug 12, 2002 at 11:03:06PM +0100, Gualter Barbas Baptista wrote:
|[...]
|
|>|>>GRASS:~ > i.tm.dehaze inverno.tasscap.4 b1 b2 b3 b4 b5 b7
|>|>>r.stats: 100%
|>|>>1 variables
|>|>>0 observations
|>|>>ERROR: SVDCMP: You must augment A with extra zero rows
|
|>|With my TM data it runs well.
|>But only with a smaller region or with the whole image?
|
|It should be sufficient to zoom a, say 500x500 region and run it
|again (since GRASS raster is region sensitive).

It works well with a smaller region. But now I have the problem of not
"dehazing" the whole scene. Is there any simple way of dehazing the
whole scene or will I have to do something like cut, dehaze and put
together again?

I will probably not need to dehaze the whole scene for the work I'm
doing now, but for the future this might prove necessary.

Is this a bug of r.linear.regression? Would this bug fix be very
complicated?

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

GAIA - Grupo de Acção e Intervenção Ambiental
ae-gaia@students.fct.unl.pt
Portugal
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6

On Tue, Aug 13, 2002 at 01:12:53AM +0100, Gualter Barbas Baptista wrote:

Markus Neteler wrote:
|On Mon, Aug 12, 2002 at 11:03:06PM +0100, Gualter Barbas Baptista wrote:
|[...]
|>|>>GRASS:~ > i.tm.dehaze inverno.tasscap.4 b1 b2 b3 b4 b5 b7
|>|>>r.stats: 100%
|>|>>1 variables
|>|>>0 observations
|>|>>ERROR: SVDCMP: You must augment A with extra zero rows
|
|>|With my TM data it runs well.
|>But only with a smaller region or with the whole image?
|
|It should be sufficient to zoom a, say 500x500 region and run it
|again (since GRASS raster is region sensitive).

It works well with a smaller region. But now I have the problem of not
"dehazing" the whole scene. Is there any simple way of dehazing the
whole scene or will I have to do something like cut, dehaze and put
together again?

The problem of locally dehazing and then merging the results is that the
linear regression will slightly differ. That means that the areas
do not match 100%, some will be better, some less good dehazed.
The only solution is to dehaze all-in-one.

I will probably not need to dehaze the whole scene for the work I'm
doing now, but for the future this might prove necessary.

Is this a bug of r.linear.regression? Would this bug fix be very
complicated?

It is not a bug, but a limitation. r.linear.regression reads from
ASCII file and then does the regression. An idea may be to replace
this regression tool with a better software allowing for large
data sets. The script i.tm.dehaze itself is very simple.

Maybe some other developer knows about a (linear) regression tool
which accepts large data sets and operates in the style of
r.linear.regression?

Markus