Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Luigi Pirelli]

follows these steps

1) install plugin "reload" that allow you to reload plugin (e.g.
processing) without restart qgis... this is useful to test your algoritm.
Btw, for the nature of some temporary path classes in aprocessing, the
plugin would continue to generate temporary stuffs in the session id of the
previous processing session... in few word, reload processiong can have
some side effects. btw this are side effects only for developers

2) clone the qgis code in https://github.com/qgis/QGIS
3) read carefully the guide in:
https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/grass7.txt
(r in your local clone)
4) find a similar grass algoritm to that has similar input or output
prameters => step 5
5) check how the interface is specified in one of descriptors in
https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/description
6) generate you new alg descriptor in
https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/description
7) copy the entire directory in the your local plugin directory (depends on
platform) or do a link directly to
https://github.com/qgis/QGIS/blob/master/python/plugins/processing/
8) reload processing plugin (or restart qgis) and test
9) open
https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/TODO.md
10) repeat from 6 until TODO list is empty ;)

cheers and thanks to add support to another algorithm... as you can see any
qgis user can develop the correct interface to grass algorithms giving an
important contribution to the community.

Luigi Pirelli

**
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*
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* Hire me: http://goo.gl/BYRQKg
**


On Fri, 16 Nov 2018 at 01:38, Francois Chartier 
wrote:

> Hi
>
> I am not a coder but i have some time and perseverence to integrate this
> module in qgis, but I would need guidance. Is anybody interested?
>  This tool would be great for a lot of discipline in environmental, soil
> sciences etc.
>
> On Mon, Oct 29, 2018, 04:12 Luigi Pirelli 
>> Hi Francois
>>
>> is it just matter to create appropriate algorithm descriptop in qgis
>> core? e.g. doing a Pull Request (with tsts) to have the algoritym supported?
>>
>> This guid sould give you the appropriate hints
>> https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/grass7.txt
>> and obviously all the descriptors available in:
>>
>> https://github.com/qgis/QGIS/tree/master/python/plugins/processing/algs/grass7/description
>>
>> this is one of the QGIS part where users can help a lot adding new
>> backend algorithms with related tests. To create tests for a not tested
>> algorithms please see this guide:
>>
>> http://www.opengis.ch/2016/02/04/increasing-the-stability-of-processing-algorithms/
>>
>> a TODO list for grass is here:
>>
>> https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/TODO.md
>>
>> regards
>>
>> Luigi Pirelli
>>
>>
>> **
>> * LinkedIn: https://www.linkedin.com/in/luigipirelli
>> * Stackexchange: http://gis.stackexchange.com/users/19667/luigi-pirelli
>> * GitHub: https://github.com/luipir
>> * Mastering QGIS 2nd Edition:
>> *
>> https://www.packtpub.com/big-data-and-business-intelligence/mastering-qgis-second-edition
>> * Hire me: http://goo.gl/BYRQKg
>>
>> **
>>
>>
>> On Sun, 28 Oct 2018 at 16:01, Francois Chartier 
>> wrote:
>>
>>> Hi
>>>
>>> Is the plugin v vol rst available from within qgis?  i didnt see it in
>>> the list of vector plugin from grass.
>>> i am looking for a 3d interpolator and i believe only grass can do this
>>> in open source.
>>> Are there other plugins that can do 3d interpolation?
>>> by 3d i am not referring to interpolation of elevation, but by
>>> interpolation of 3d dataset with xyz + attribute (ex: soil moisture), with
>>> data points vertically stacked, and would need to interpolate verically and
>>> horizontally.
>>>
>>> thks
>>> f
>>> ___
>>> Qgis-user mailing list
>>> Qgis-user@lists.osgeo.org
>>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>>
>>
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Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Francois Chartier]

Hi

I am not a coder but i have some time and perseverence to integrate this
module in qgis, but I would need guidance. Is anybody interested?
 This tool would be great for a lot of discipline in environmental, soil
sciences etc.

On Mon, Oct 29, 2018, 04:12 Luigi Pirelli  Hi Francois
>
> is it just matter to create appropriate algorithm descriptop in qgis core?
> e.g. doing a Pull Request (with tsts) to have the algoritym supported?
>
> This guid sould give you the appropriate hints
> https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/grass7.txt
> and obviously all the descriptors available in:
>
> https://github.com/qgis/QGIS/tree/master/python/plugins/processing/algs/grass7/description
>
> this is one of the QGIS part where users can help a lot adding new backend
> algorithms with related tests. To create tests for a not tested algorithms
> please see this guide:
>
> http://www.opengis.ch/2016/02/04/increasing-the-stability-of-processing-algorithms/
>
> a TODO list for grass is here:
>
> https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/TODO.md
>
> regards
>
> Luigi Pirelli
>
>
> **
> * LinkedIn: https://www.linkedin.com/in/luigipirelli
> * Stackexchange: http://gis.stackexchange.com/users/19667/luigi-pirelli
> * GitHub: https://github.com/luipir
> * Mastering QGIS 2nd Edition:
> *
> https://www.packtpub.com/big-data-and-business-intelligence/mastering-qgis-second-edition
> * Hire me: http://goo.gl/BYRQKg
>
> **
>
>
> On Sun, 28 Oct 2018 at 16:01, Francois Chartier 
> wrote:
>
>> Hi
>>
>> Is the plugin v vol rst available from within qgis?  i didnt see it in
>> the list of vector plugin from grass.
>> i am looking for a 3d interpolator and i believe only grass can do this
>> in open source.
>> Are there other plugins that can do 3d interpolation?
>> by 3d i am not referring to interpolation of elevation, but by
>> interpolation of 3d dataset with xyz + attribute (ex: soil moisture), with
>> data points vertically stacked, and would need to interpolate verically and
>> horizontally.
>>
>> thks
>> f
>> ___
>> Qgis-user mailing list
>> Qgis-user@lists.osgeo.org
>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
>
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Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Francois Chartier]

If it is "just the matter" is it something approachable by non coder person
and how many hrs roughly 10 or 100 hrs of work?

Le lun. 29 oct. 2018 à 04:12, Luigi Pirelli  a écrit :

> Hi Francois
>
> is it just matter to create appropriate algorithm descriptop in qgis core?
> e.g. doing a Pull Request (with tsts) to have the algoritym supported?
>
> This guid sould give you the appropriate hints
> https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/grass7.txt
> and obviously all the descriptors available in:
>
> https://github.com/qgis/QGIS/tree/master/python/plugins/processing/algs/grass7/description
>
> this is one of the QGIS part where users can help a lot adding new backend
> algorithms with related tests. To create tests for a not tested algorithms
> please see this guide:
>
> http://www.opengis.ch/2016/02/04/increasing-the-stability-of-processing-algorithms/
>
> a TODO list for grass is here:
>
> https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/TODO.md
>
> regards
>
> Luigi Pirelli
>
>
> **
> * LinkedIn: https://www.linkedin.com/in/luigipirelli
> * Stackexchange: http://gis.stackexchange.com/users/19667/luigi-pirelli
> * GitHub: https://github.com/luipir
> * Mastering QGIS 2nd Edition:
> *
> https://www.packtpub.com/big-data-and-business-intelligence/mastering-qgis-second-edition
> * Hire me: http://goo.gl/BYRQKg
>
> **
>
>
> On Sun, 28 Oct 2018 at 16:01, Francois Chartier 
> wrote:
>
>> Hi
>>
>> Is the plugin v vol rst available from within qgis?  i didnt see it in
>> the list of vector plugin from grass.
>> i am looking for a 3d interpolator and i believe only grass can do this
>> in open source.
>> Are there other plugins that can do 3d interpolation?
>> by 3d i am not referring to interpolation of elevation, but by
>> interpolation of 3d dataset with xyz + attribute (ex: soil moisture), with
>> data points vertically stacked, and would need to interpolate verically and
>> horizontally.
>>
>> thks
>> f
>> ___
>> Qgis-user mailing list
>> Qgis-user@lists.osgeo.org
>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
>
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Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Luigi Pirelli]

Hi Francois

is it just matter to create appropriate algorithm descriptop in qgis core?
e.g. doing a Pull Request (with tsts) to have the algoritym supported?

This guid sould give you the appropriate hints
https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/grass7.txt
and obviously all the descriptors available in:
https://github.com/qgis/QGIS/tree/master/python/plugins/processing/algs/grass7/description

this is one of the QGIS part where users can help a lot adding new backend
algorithms with related tests. To create tests for a not tested algorithms
please see this guide:
http://www.opengis.ch/2016/02/04/increasing-the-stability-of-processing-algorithms/

a TODO list for grass is here:
https://github.com/qgis/QGIS/blob/master/python/plugins/processing/algs/grass7/TODO.md

regards

Luigi Pirelli

**
* LinkedIn: https://www.linkedin.com/in/luigipirelli
* Stackexchange: http://gis.stackexchange.com/users/19667/luigi-pirelli
* GitHub: https://github.com/luipir
* Mastering QGIS 2nd Edition:
*
https://www.packtpub.com/big-data-and-business-intelligence/mastering-qgis-second-edition
* Hire me: http://goo.gl/BYRQKg
**


On Sun, 28 Oct 2018 at 16:01, Francois Chartier 
wrote:

> Hi
>
> Is the plugin v vol rst available from within qgis?  i didnt see it in the
> list of vector plugin from grass.
> i am looking for a 3d interpolator and i believe only grass can do this in
> open source.
> Are there other plugins that can do 3d interpolation?
> by 3d i am not referring to interpolation of elevation, but by
> interpolation of 3d dataset with xyz + attribute (ex: soil moisture), with
> data points vertically stacked, and would need to interpolate verically and
> horizontally.
>
> thks
> f
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Nicolas Cadieux]

Hi,

The last I played with Kriging, you could only take into account the x,y, plus 
on variable that you call “m”.  It does not take into account any other 
variable like altitude (z).  As a good Kriging interpolation relies on the 
distribution of m on the x and y plane and that each m variable may behave 
differently on the variogram, I don’t see how you could do this in one shot 
using Kriging. You can do this with more simple algorithms like IDW, but not 
Kriging.  

If there is a multi variable version of Kriging that I don’t know, point it to 
me.  I would like to read on it.

Nicolas


> Le 28 oct. 2018 à 15:06, Benjamin Ducke  a écrit :
> 
> Hi,
> 
>> On 28/10/2018 18:46, Nicolas Cadieux wrote:
>> Hi, 
>> Some form of Kriging is probably best. Â But it requires a very good
>> understanding of each data set and its distribution on the variogramme.
>> Â Make sure you study each variable separately for each layer. 
> 
> I don't think "separately" would be a good idea.
> 
> Kriging (like all spatial interpolators) is
> fundamentally based on a concept of spatial
> distance: measurements that are closer to the
> location at which to interpolate have more
> influence on the result than measurements
> that are further away. In your case, "closer"
> means "closer in 3D space". If you slice up
> your data and consider each slice separately,
> then the interpolation will be blind for
> measurements that lie closely on the Z axis
> and should actually weigh in heavily. The
> resulting 2D layers will then be heavily biased
> towards trends on the X-Y plane.
> 
> I am not aware of any open source software
> that can perform kriging of "m" at "X/Y/Z"
> locations, but I would love to learn of one.
> 
> But I think you really need to consider using
> GRASS GIS with its native interface and
> running "v.vol.rst " on your data. That's a
> spline-based interpolation method that has
> been shown to give good results for continuous
> environmental data:
> 
> https://grass.osgeo.org/grass72/manuals/v.vol.rst.html
> 
> The result will be a 3D raster that QGIS
> cannot handle. But you can use the native
> GRASS modules to slice your data by Z range
> and export into GeoTIFFs that you can then
> stack on top of each other in QGIS.
> 
> There is some documentation about 3D raster
> processing in GRASS GIS here:
> 
> https://grasswiki.osgeo.org/wiki/Voxel
> https://grasswiki.osgeo.org/wiki/Help_with_3D
> 
> But you will probably be better advised to
> contact the GRASS user list for more help
> on this:
> 
> https://grass.osgeo.org/support/mailing-lists/
> 
> Best,
> 
> Ben
> 
>> If you
>> need to query the data first and save the result to a new file, that
>> will be two steps. Â Having only the data you need will reduce the amount
>> of manipulation errors. Â Keeping track of data manipulation is easy if
>> you have a good file convention. Â Ex data.shp becomes 
>> data_query_z<250.shp. 
>> Good luck,
>> Nicolas
>> 
>> Le 28 oct. 2018 Ã  13:29, Francois Chartier > > a ÃHi,
> 
>> On 28/10/2018 18:46, Nicolas Cadieux wrote:
>> Hi, 
>> Some form of Kriging is probably best. Â But it requires a very good
>> understanding of each data set and its distribution on the variogramme.
>> Â Make sure you study each variable separately for each layer. 
> 
> I don't think "separately" would be a good idea.
> 
> Kriging (like all spatial interpolators) is
> fundamentally based on a concept of spatial
> distance: measurements that are closer to the
> location at which to interpolate have more
> influence on the result than measurements
> that are further away. In your case, "closer"
> means "closer in 3D space". If you slice up
> your data and consider each slice separately,
> then the interpolation will be blind for
> measurements that lie closely on the Z axis
> and should actually weigh in heavily. The
> resulting 2D layers will then be heavily biased
> towards trends on the X-Y plane.
> 
> I am not aware of any open source software
> that can perform kriging of "m" at "X/Y/Z"
> locations, but I would love to learn of one.
> 
> But I think you really need to consider using
> GRASS GIS with its native interface and
> running "v.vol.rst " on your data. That's a
> spline-based interpolation method that has
> been shown to give good results for continuous
> environmental data:
> 
> https://grass.osgeo.org/grass72/manuals/v.vol.rst.html
> 
> The result will be a 3D raster that QGIS
> cannot handle. But you can use the native
> GRASS modules to slice your data by Z range
> and export into GeoTIFFs that you can then
> stack on top of each other in QGIS.
> 
> There is some documentation about 3D raster
> processing in GRASS GIS here:
> 
> https://grasswiki.osgeo.org/wiki/Voxel
> https://grasswiki.osgeo.org/wiki/Help_with_3D
> 
> But you will probably be better advised to
> contact the GRASS user list for more help
> on this:
> 
> https://grass.osgeo.org/support/mailing-lists/
> 
> Best,
> 
> Ben
> 
>> If you

Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Benjamin Ducke]

Hi,

On 28/10/2018 18:46, Nicolas Cadieux wrote:
> Hi, 
> Some form of Kriging is probably best.  But it requires a very good
> understanding of each data set and its distribution on the variogramme.
>  Make sure you study each variable separately for each layer. 

I don't think "separately" would be a good idea.

Kriging (like all spatial interpolators) is
fundamentally based on a concept of spatial
distance: measurements that are closer to the
location at which to interpolate have more
influence on the result than measurements
that are further away. In your case, "closer"
means "closer in 3D space". If you slice up
your data and consider each slice separately,
then the interpolation will be blind for
measurements that lie closely on the Z axis
and should actually weigh in heavily. The
resulting 2D layers will then be heavily biased
towards trends on the X-Y plane.

I am not aware of any open source software
that can perform kriging of "m" at "X/Y/Z"
locations, but I would love to learn of one.

But I think you really need to consider using
GRASS GIS with its native interface and
running "v.vol.rst " on your data. That's a
spline-based interpolation method that has
been shown to give good results for continuous
environmental data:

https://grass.osgeo.org/grass72/manuals/v.vol.rst.html

The result will be a 3D raster that QGIS
cannot handle. But you can use the native
GRASS modules to slice your data by Z range
and export into GeoTIFFs that you can then
stack on top of each other in QGIS.

There is some documentation about 3D raster
processing in GRASS GIS here:

https://grasswiki.osgeo.org/wiki/Voxel
https://grasswiki.osgeo.org/wiki/Help_with_3D

But you will probably be better advised to
contact the GRASS user list for more help
on this:

https://grass.osgeo.org/support/mailing-lists/

Best,

Ben

> If you
> need to query the data first and save the result to a new file, that
> will be two steps.  Having only the data you need will reduce the amount
> of manipulation errors.  Keeping track of data manipulation is easy if
> you have a good file convention.  Ex data.shp becomes data_query_z<250.shp. 
> Good luck,
> Nicolas
> 
> Le 28 oct. 2018 à 13:29, Francois Chartier  > a écrit :
> 
>> I am trying to interpolate particle size of soils, which i will then
>> transform into a permeability. 
>> the option to stack multiple raster is the path i am going to use, and
>> i think kriging is the probably the most suited for soil properties.
>> Inverse distance should be good and lighter in terms of computation. 
>> i have to figure out to run the interpolation based on a query
>> result.  i am not sure if this has to be a 2 step process or 1 step. 
>>
>> On Sun, Oct 28, 2018, 11:34 Nicolas Cadieux,
>> mailto:nicolas.cadi...@archeotec.ca>>
>> wrote:
>>
>> Hi,
>>
>> This is interesting.  Basically the end result is a multi band
>> raster, which can also be done by stacking multiple band rasters. 
>> I don’t know anything about this v.vol.rst algorithm but it sound
>> interesting. I do do see a problem though. Your data sets may not
>> all like to be interpolated with a single algorithm. So unless you
>> can modify the interpolation algorithm for each  band, you will
>> probably end up with a bad raster data set.  The chosen algorithm
>> must work like the phenomenon you are trying to study.
>>
>> As an example, using a simple TIN to predict the weather will most
>> likely fail as weather pattern don’t work like a TIN. Inverse
>> distance weight would probably be better. 
>>
>> Nicolas
>>
>> > Le 28 oct. 2018 à 11:00, Francois Chartier
>> mailto:fra.chart...@gmail.com>> a écrit :
>> >
>> > Hi
>> >
>> > Is the plugin v vol rst available from within qgis?  i didnt see
>> it in the list of vector plugin from grass.
>> > i am looking for a 3d interpolator and i believe only grass can
>> do this in open source. 
>> > Are there other plugins that can do 3d interpolation? 
>> > by 3d i am not referring to interpolation of elevation, but by
>> interpolation of 3d dataset with xyz + attribute (ex: soil
>> moisture), with data points vertically stacked, and would need to
>> interpolate verically and horizontally. 
>> >
>> > thks
>> > f
>> > ___
>> > Qgis-user mailing list
>> > Qgis-user@lists.osgeo.org 
>> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>>
> 
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
> 



-- 
Dr. Benjamin Ducke
Deutsches Archäologisches Institut (DAI)
Zentrale Berlin, IT-Referat

Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Francois Chartier]

Thanks for the tip!

On Sun, Oct 28, 2018, 13:46 Nicolas Cadieux, 
wrote:

> Hi,
> Some form of Kriging is probably best.  But it requires a very good
> understanding of each data set and its distribution on the variogramme.
> Make sure you study each variable separately for each layer. If you need to
> query the data first and save the result to a new file, that will be two
> steps.  Having only the data you need will reduce the amount of
> manipulation errors.  Keeping track of data manipulation is easy if you
> have a good file convention.  Ex data.shp becomes data_query_z<250.shp.
> Good luck,
> Nicolas
>
> Le 28 oct. 2018 à 13:29, Francois Chartier  a
> écrit :
>
> I am trying to interpolate particle size of soils, which i will then
> transform into a permeability.
> the option to stack multiple raster is the path i am going to use, and i
> think kriging is the probably the most suited for soil properties. Inverse
> distance should be good and lighter in terms of computation.
> i have to figure out to run the interpolation based on a query result.  i
> am not sure if this has to be a 2 step process or 1 step.
>
> On Sun, Oct 28, 2018, 11:34 Nicolas Cadieux, 
> wrote:
>
>> Hi,
>>
>> This is interesting.  Basically the end result is a multi band raster,
>> which can also be done by stacking multiple band rasters.  I don’t know
>> anything about this v.vol.rst algorithm but it sound interesting. I do do
>> see a problem though. Your data sets may not all like to be interpolated
>> with a single algorithm. So unless you can modify the interpolation
>> algorithm for each  band, you will probably end up with a bad raster data
>> set.  The chosen algorithm must work like the phenomenon you are trying to
>> study.
>>
>> As an example, using a simple TIN to predict the weather will most likely
>> fail as weather pattern don’t work like a TIN. Inverse distance weight
>> would probably be better.
>>
>> Nicolas
>>
>> > Le 28 oct. 2018 à 11:00, Francois Chartier  a
>> écrit :
>> >
>> > Hi
>> >
>> > Is the plugin v vol rst available from within qgis?  i didnt see it in
>> the list of vector plugin from grass.
>> > i am looking for a 3d interpolator and i believe only grass can do this
>> in open source.
>> > Are there other plugins that can do 3d interpolation?
>> > by 3d i am not referring to interpolation of elevation, but by
>> interpolation of 3d dataset with xyz + attribute (ex: soil moisture), with
>> data points vertically stacked, and would need to interpolate verically and
>> horizontally.
>> >
>> > thks
>> > f
>> > ___
>> > Qgis-user mailing list
>> > Qgis-user@lists.osgeo.org
>> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>>
>
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Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Nicolas Cadieux]

Hi, 
Some form of Kriging is probably best.  But it requires a very good 
understanding of each data set and its distribution on the variogramme.  Make 
sure you study each variable separately for each layer. If you need to query 
the data first and save the result to a new file, that will be two steps.  
Having only the data you need will reduce the amount of manipulation errors.  
Keeping track of data manipulation is easy if you have a good file convention.  
Ex data.shp becomes data_query_z<250.shp. 
Good luck,
Nicolas

> Le 28 oct. 2018 à 13:29, Francois Chartier  a écrit :
> 
> I am trying to interpolate particle size of soils, which i will then 
> transform into a permeability. 
> the option to stack multiple raster is the path i am going to use, and i 
> think kriging is the probably the most suited for soil properties. Inverse 
> distance should be good and lighter in terms of computation. 
> i have to figure out to run the interpolation based on a query result.  i am 
> not sure if this has to be a 2 step process or 1 step. 
> 
>> On Sun, Oct 28, 2018, 11:34 Nicolas Cadieux,  
>> wrote:
>> Hi,
>> 
>> This is interesting.  Basically the end result is a multi band raster, which 
>> can also be done by stacking multiple band rasters.  I don’t know anything 
>> about this v.vol.rst algorithm but it sound interesting. I do do see a 
>> problem though. Your data sets may not all like to be interpolated with a 
>> single algorithm. So unless you can modify the interpolation algorithm for 
>> each  band, you will probably end up with a bad raster data set.  The chosen 
>> algorithm must work like the phenomenon you are trying to study.
>> 
>> As an example, using a simple TIN to predict the weather will most likely 
>> fail as weather pattern don’t work like a TIN. Inverse distance weight would 
>> probably be better.  
>> 
>> Nicolas
>> 
>> > Le 28 oct. 2018 à 11:00, Francois Chartier  a 
>> > écrit :
>> > 
>> > Hi
>> > 
>> > Is the plugin v vol rst available from within qgis?  i didnt see it in the 
>> > list of vector plugin from grass. 
>> > i am looking for a 3d interpolator and i believe only grass can do this in 
>> > open source.  
>> > Are there other plugins that can do 3d interpolation?  
>> > by 3d i am not referring to interpolation of elevation, but by 
>> > interpolation of 3d dataset with xyz + attribute (ex: soil moisture), with 
>> > data points vertically stacked, and would need to interpolate verically 
>> > and horizontally.  
>> > 
>> > thks
>> > f
>> > ___
>> > Qgis-user mailing list
>> > Qgis-user@lists.osgeo.org
>> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Francois Chartier]

I am trying to interpolate particle size of soils, which i will then
transform into a permeability.
the option to stack multiple raster is the path i am going to use, and i
think kriging is the probably the most suited for soil properties. Inverse
distance should be good and lighter in terms of computation.
i have to figure out to run the interpolation based on a query result.  i
am not sure if this has to be a 2 step process or 1 step.

On Sun, Oct 28, 2018, 11:34 Nicolas Cadieux, 
wrote:

> Hi,
>
> This is interesting.  Basically the end result is a multi band raster,
> which can also be done by stacking multiple band rasters.  I don’t know
> anything about this v.vol.rst algorithm but it sound interesting. I do do
> see a problem though. Your data sets may not all like to be interpolated
> with a single algorithm. So unless you can modify the interpolation
> algorithm for each  band, you will probably end up with a bad raster data
> set.  The chosen algorithm must work like the phenomenon you are trying to
> study.
>
> As an example, using a simple TIN to predict the weather will most likely
> fail as weather pattern don’t work like a TIN. Inverse distance weight
> would probably be better.
>
> Nicolas
>
> > Le 28 oct. 2018 à 11:00, Francois Chartier  a
> écrit :
> >
> > Hi
> >
> > Is the plugin v vol rst available from within qgis?  i didnt see it in
> the list of vector plugin from grass.
> > i am looking for a 3d interpolator and i believe only grass can do this
> in open source.
> > Are there other plugins that can do 3d interpolation?
> > by 3d i am not referring to interpolation of elevation, but by
> interpolation of 3d dataset with xyz + attribute (ex: soil moisture), with
> data points vertically stacked, and would need to interpolate verically and
> horizontally.
> >
> > thks
> > f
> > ___
> > Qgis-user mailing list
> > Qgis-user@lists.osgeo.org
> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
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Re: [Qgis-user] Fwd: qgis - v.vol.rst from grass

[Nicolas Cadieux]

Hi,

This is interesting.  Basically the end result is a multi band raster, which 
can also be done by stacking multiple band rasters.  I don’t know anything 
about this v.vol.rst algorithm but it sound interesting. I do do see a problem 
though. Your data sets may not all like to be interpolated with a single 
algorithm. So unless you can modify the interpolation algorithm for each  band, 
you will probably end up with a bad raster data set.  The chosen algorithm must 
work like the phenomenon you are trying to study.

As an example, using a simple TIN to predict the weather will most likely fail 
as weather pattern don’t work like a TIN. Inverse distance weight would 
probably be better.  

Nicolas

> Le 28 oct. 2018 à 11:00, Francois Chartier  a écrit :
> 
> Hi
> 
> Is the plugin v vol rst available from within qgis?  i didnt see it in the 
> list of vector plugin from grass. 
> i am looking for a 3d interpolator and i believe only grass can do this in 
> open source.  
> Are there other plugins that can do 3d interpolation?  
> by 3d i am not referring to interpolation of elevation, but by interpolation 
> of 3d dataset with xyz + attribute (ex: soil moisture), with data points 
> vertically stacked, and would need to interpolate verically and horizontally. 
>  
> 
> thks
> f
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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[Qgis-user] Fwd: qgis - v.vol.rst from grass

[Francois Chartier]

Hi

Is the plugin v vol rst available from within qgis?  i didnt see it in the
list of vector plugin from grass.
i am looking for a 3d interpolator and i believe only grass can do this in
open source.
Are there other plugins that can do 3d interpolation?
by 3d i am not referring to interpolation of elevation, but by
interpolation of 3d dataset with xyz + attribute (ex: soil moisture), with
data points vertically stacked, and would need to interpolate verically and
horizontally.

thks
f
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