I’m not sure if this is a bug or if I just don’t know how to use v.surf.bspline.
If I make a 3D vector point map, v.surf.bspline will interpolate using the z-coordinate fine.
However, if I try to specify a vector column as the basis for interpolation, it will go through fine, but the result is a flat map. That is, it seems not to correctly recognize a column specified for interpolation. I set layer=1, but don’t see what else I should do. Any suggestions?
Michael
Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University
phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton
Hi Michael and all,
Michael Barton escribió:
However, if I try to specify a vector column as the basis for interpolation,
it will go through fine, but the result is a flat map. That is, it seems not
to correctly recognize a column specified for interpolation. I set layer=1,
but don't see what else I should do. Any suggestions?
Is it completely flat? I mean, did you try to take a look to the raster values? Time ago, border errors (due to the interpolation) made visualization a bit odd because, in borders, v.surf.bspline try to interpolate to zero. So depending on the values you want to interpolate it will seem that the whole raster has the same value but really it hasn't. I thought this error was fixed already, though. Which version are you using?
I don't know whether is this or not, so let me know and I'll proceed with the bugfixing -in case there exits any bug ;)-. In the meanwhile I'll try to find the dataset I used in my tests and I'll check too.
Regards,
Roberto.
--
Roberto Antolín Sánchez
Politecnico di Milano - Polo Regionale di Como
(Laboratorio di Geomatica V2.8)
Via Valleggio, 11 - 22100 Como, Italy
tel: +39 031 332 7533 || fax: +39 031 332 7519
roberto@geomatica.como.polimi.it
It's completely flat. I just did another test. If I use a vector attribute
column in layer 1, the entire interpolated map has a value of 0 for all
cells. If I create a 3D vector with the same data and set layer=0 so that it
uses z values, it works fine.
So I guess it sounds like a bug.
Michael
On 10/11/07 1:56 AM, "Roberto Antolin" <roberto@geomatica.como.polimi.it>
wrote:
Hi Michael and all,
Michael Barton escribió:
However, if I try to specify a vector column as the basis for interpolation,
it will go through fine, but the result is a flat map. That is, it seems not
to correctly recognize a column specified for interpolation. I set layer=1,
but don't see what else I should do. Any suggestions?
Is it completely flat? I mean, did you try to take a look to the raster
values? Time ago, border errors (due to the interpolation) made
visualization a bit odd because, in borders, v.surf.bspline try to
interpolate to zero. So depending on the values you want to interpolate
it will seem that the whole raster has the same value but really it
hasn't. I thought this error was fixed already, though. Which version
are you using?
I don't know whether is this or not, so let me know and I'll proceed
with the bugfixing -in case there exits any bug ;)-. In the meanwhile
I'll try to find the dataset I used in my tests and I'll check too.
Regards,
Roberto.
__________________________________________
Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University
phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton
Hi Michael and all,
Sorry for the delay but I wasn't able to find what was wrong and then we had some big problems with our server.
Michael Barton escribió:
It's completely flat. I just did another test. If I use a vector attribute
column in layer 1, the entire interpolated map has a value of 0 for all
cells. If I create a 3D vector with the same data and set layer=0 so that it
uses z values, it works fine.
So I guess it sounds like a bug.
You were right! I made some new tests with other datasets and now it is supposed to be fixed. It was an error when reading the categories for the chosen layer.
Ciao,
Roberto.
--
Roberto Antolín Sánchez
Politecnico di Milano - Polo Regionale di Como
(Laboratorio di Geomatica V2.8)
Via Valleggio, 11 - 22100 Como, Italy
tel: +39 031 332 7533 || fax: +39 031 332 7519
roberto@geomatica.como.polimi.it
Roberto Antolin wrote:
Hi Michael and all,
Sorry for the delay but I wasn't able to find what was wrong and then we
had some big problems with our server.
Michael Barton escribió:
It's completely flat. I just did another test. If I use a vector
attribute
column in layer 1, the entire interpolated map has a value of 0 for all
cells. If I create a 3D vector with the same data and set layer=0 so that
it
uses z values, it works fine.
So I guess it sounds like a bug.
You were right! I made some new tests with other datasets and now it is
supposed to be fixed. It was an error when reading the categories for
the chosen layer.
Ciao,
Roberto.
Thanks for fixing it (Michael, please report if it now works for you).
Do we need to backport this to 6.2.3?
Markus
--
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