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Distance map with defined path

9 messages

Distance map with defined path

Reply Threaded

Hi List!

I was wondering if there is a way to obtain a (raster) map of distances
from a point or a line, in which the path is defined by a map (i.e. a
flow direction).
It would be very useful for me!

Thank you in advance.

Cheers
m.

--
Ing. Margherita Di Leo
Ph.D. Student
Methods and Technologies for Environmental Monitoring
Department of Environmental Engineering and Physics (DIFA)

University of Basilicata
Campus Macchia Romana
85100 - Potenza
Italy

Office: +39-0971205363
Fax: +39-0971205160
E-mail: dileomargherita AT gmail DOT com
Skype: dileomargherita
URL: http://www.difa.unibas.it/A_Manager_PP.do?azione=visualizzaHomePage&id=106

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Jachym Cepicky

Re: Distance map with defined path

Reply Threaded

Hi,

would [1] help ?

[1] http://grass.osgeo.org/grass64/manuals/html64_user/r.grow.distance.html

Jachym

On Thu, Jul 09, 2009 at 03:29:40PM +0200, Margherita Di Leo wrote:

> Hi List!
>
> I was wondering if there is a way to obtain a (raster) map of distances
> from a point or a line, in which the path is defined by a map (i.e. a
> flow direction).
> It would be very useful for me!
>
> Thank you in advance.
>
> Cheers
> m.
>
> --
> Ing. Margherita Di Leo
> Ph.D. Student Methods and Technologies for Environmental Monitoring
> Department of Environmental Engineering and Physics (DIFA)
>
> University of Basilicata Campus Macchia Romana
> 85100 - Potenza Italy
>
> Office: +39-0971205363
> Fax: +39-0971205160
> E-mail: dileomargherita AT gmail DOT com
> Skype: dileomargherita
> URL: http://www.difa.unibas.it/A_Manager_PP.do?azione=visualizzaHomePage&id=106
>
>
>
>
>
> _______________________________________________
> grass-user mailing list
> [hidden email]
> http://lists.osgeo.org/mailman/listinfo/grass-user

--
Jachym Cepicky
e-mail: jachym.cepicky gmail com
URL: http://les-ejk.cz
GPG: http://www.les-ejk.cz/pgp/JachymCepicky.pgp
Key fingerprint: 0C6D 0EAE 76BD 506C F299 ED8A C8AB 74B8 08D4 E08F

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margherita

Re: Distance map with defined path

Reply Threaded

Hi Jachym,

Thank you very much for your answer.

I think I was not very clear in explaining my problem. I have to
calculate distance from a line, but the distance has to be calculated
*following a path*, defined by a matrix of direction, as a 'flow
direction' in hydrology. It would be a very useful hydrological tool.

Cheers

m.

Jachym Cepicky wrote:

> Hi,
>
> would [1] help ?
>
>
> [1] http://grass.osgeo.org/grass64/manuals/html64_user/r.grow.distance.html
>
> Jachym
>
> On Thu, Jul 09, 2009 at 03:29:40PM +0200, Margherita Di Leo wrote:
>
>> Hi List!
>>
>> I was wondering if there is a way to obtain a (raster) map of distances
>> from a point or a line, in which the path is defined by a map (i.e. a
>> flow direction).
>> It would be very useful for me!
>>
>> Thank you in advance.
>>
>> Cheers
>> m.
>>
>>

--
Eng. Margherita Di Leo
Ph.D. Student
Methods and Technologies for Environmental Monitoring
Department of Environmental Engineering and Physics (DIFA)

University of Basilicata
Campus Macchia Romana
85100 - Potenza
Italy

Office: +39-0971205363
Fax: +39-0971205160
E-mail: dileomargherita AT gmail DOT com
Skype: dileomargherita
URL: http://www.difa.unibas.it/A_Manager_PP.do?azione=visualizzaHomePage&id=106

_______________________________________________
grass-user mailing list
[hidden email]
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Milton Cezar Ribeiro

Re: Distance map with defined path

Reply Threaded

Hi Margherita,

give a look at

r.watershed

r.terraflow

r.flow

Good luck,

milton

2009/7/10 Margherita Di Leo <[hidden email]>

Hi Jachym,

Thank you very much for your answer.

I think I was not very clear in explaining my problem. I have to calculate distance from a line, but the distance has to be calculated *following a path*, defined by a matrix of direction, as a 'flow direction' in hydrology. It would be a very useful hydrological tool.

Cheers

m.

Jachym Cepicky wrote:

Hi,

would [1] help ?

[1] http://grass.osgeo.org/grass64/manuals/html64_user/r.grow.distance.html

Jachym

On Thu, Jul 09, 2009 at 03:29:40PM +0200, Margherita Di Leo wrote:

Hi List!

I was wondering if there is a way to obtain a (raster) map of distances from a point or a line, in which the path is defined by a map (i.e. a flow direction).
It would be very useful for me!

Thank you in advance.

Cheers
m.

--
Eng. Margherita Di Leo
Ph.D. Student Methods and Technologies for Environmental Monitoring
Department of Environmental Engineering and Physics (DIFA)

University of Basilicata Campus Macchia Romana
85100 - Potenza Italy

Office: +39-0971205363
Fax: +39-0971205160
E-mail: dileomargherita AT gmail DOT com
Skype: dileomargherita
URL: http://www.difa.unibas.it/A_Manager_PP.do?azione=visualizzaHomePage&id=106

_______________________________________________
grass-user mailing list
[hidden email]
http://lists.osgeo.org/mailman/listinfo/grass-user

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margherita

Re: Distance map with defined path

Reply Threaded

Hi Milton,
Thank you for answering,
I corrently use r.watershed to obtain my flow direction matrix
(drainage). I'm searching for a module in which I can put this
'drainage' in input, and a raster (or vector) with the river network in
input, to obtain in output a matrix in wich in each cell there is the
distance from the river, calculated on the basis of the path defined in
'drainage'.

Thank you
m.

Milton Cezar Ribeiro wrote:

> Hi Margherita,
>
> give a look at
> r.watershed
> r.terraflow
> r.flow
> Good luck,
>
> milton
> 2009/7/10 Margherita Di Leo <[hidden email]
> <mailto:[hidden email]>>
>
> Hi Jachym,
>
> Thank you very much for your answer.
>
> I think I was not very clear in explaining my problem. I have to
> calculate distance from a line, but the distance has to be
> calculated *following a path*, defined by a matrix of direction,
> as a 'flow direction' in hydrology. It would be a very useful
> hydrological tool.
>
> Cheers
>
> m.
>
>
>
> Jachym Cepicky wrote:
>
> Hi,
>
> would [1] help ?
>
>
> [1]
> http://grass.osgeo.org/grass64/manuals/html64_user/r.grow.distance.html
>
> Jachym
>
> On Thu, Jul 09, 2009 at 03:29:40PM +0200, Margherita Di Leo wrote:
>
>
> Hi List!
>
> I was wondering if there is a way to obtain a (raster) map
> of distances from a point or a line, in which the path is
> defined by a map (i.e. a flow direction).
> It would be very useful for me!
>
> Thank you in advance.
>
> Cheers
> m.
>
>
>
>

Markus Neteler

Re: Distance map with defined path

Reply Threaded

In reply to this post by margherita

On Thu, Jul 9, 2009 at 3:29 PM, Margherita Di Leo<[hidden email]> wrote:
> Hi List!
>
> I was wondering if there is a way to obtain a (raster) map of distances from
> a point or a line, in which the path is defined by a map (i.e. a flow
> direction).
> It would be very useful for me!

if I understand what you mean, r.cost should do it:
http://grass.osgeo.org/screenshots/raster.php
-> Example Distance to water (r.cost)

The r.cost manual page contains an example.

Markus
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Moritz Lennert

Re: Distance map with defined path

Reply Threaded

In reply to this post by margherita

On 10/07/09 14:00, Margherita Di Leo wrote:
> Hi Milton,
> Thank you for answering,
> I corrently use r.watershed to obtain my flow direction matrix
> (drainage). I'm searching for a module in which I can put this
> 'drainage' in input, and a raster (or vector) with the river network in
> input, to obtain in output a matrix in wich in each cell there is the
> distance from the river, calculated on the basis of the path defined in
> 'drainage'.

Maybe by setting all cells other than the drainage paths to null ? Or by
using a mask which only leaves the drainage paths ? I don't know how
r.grow.distance handles null cells ?

In vector space you could maybe use v.distance upload=to_along...

Moritz
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margherita

Re: Distance map with defined path

Reply Threaded

In reply to this post by Markus Neteler

Hi Markus,

Thanks for the hint! I'm trying with r.cost (but it is veeeeery slow!)

Cheers

margherita

Markus Neteler wrote:

> On Thu, Jul 9, 2009 at 3:29 PM, Margherita Di Leo<[hidden email]> wrote:
>
>> Hi List!
>>
>> I was wondering if there is a way to obtain a (raster) map of distances from
>> a point or a line, in which the path is defined by a map (i.e. a flow
>> direction).
>> It would be very useful for me!
>>
>
>
> if I understand what you mean, r.cost should do it:
> http://grass.osgeo.org/screenshots/raster.php
> -> Example Distance to water (r.cost)
>
> The r.cost manual page contains an example.
>
> Markus
>
>

Markus Neteler

Re: Distance map with defined path

Reply Threaded

Hi Margherita,

On Wed, Jul 15, 2009 at 8:03 AM, Margherita Di Leo<[hidden email]> wrote:
> Hi Markus,
>
> Thanks for the hint! I'm trying with r.cost (but it is veeeeery slow!)

since yesterday night (European time) r.terracost (GRASS Addons)
seem to produce reasonable results.
Please consider to try as well!

ciao
Markus
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