[GRASS-user] Missing v.generalize in Grass 6.23

GRASS GRASS user
1

Hi All,

Sorry for the newbie question, but I just finished getting GRASS 6.23 built last night and am using it for the first time today. I’ve gotten a new location created, and a shapefile imported, and now I would like to simplify the geometry. Unfortunately, it appears that v.generalize is missing.

Can someone tell me if this tool only comes with a later version of GRASS, or is it possible that I missed a build step.

Thanks,

Roger

2

Hi,

2009/4/14 Roger André <randre@gmail.com>:

Sorry for the newbie question, but I just finished getting GRASS 6.23 built
last night and am using it for the first time today. I've gotten a new
location created, and a shapefile imported, and now I would like to simplify
the geometry. Unfortunately, it appears that v.generalize is missing.

Can someone tell me if this tool only comes with a later version of GRASS,
or is it possible that I missed a build step.

v.generalize is available in GRASS >= 6.3.0. BTW, GRASS 6.2.3 is
pretty old. Try the last RC of GRASS 6.4.0 (RC4).

Regards, Martin

--
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa

3

Hi Martin,

Thanks for the info, I’ll get 6.4 installed tonight.

Roger

On Tue, Apr 14, 2009 at 3:23 PM, Martin Landa <landa.martin@gmail.com> wrote:

Hi,

2009/4/14 Roger André <randre@gmail.com>:

Sorry for the newbie question, but I just finished getting GRASS 6.23 built
last night and am using it for the first time today. I’ve gotten a new
location created, and a shapefile imported, and now I would like to simplify
the geometry. Unfortunately, it appears that v.generalize is missing.

Can someone tell me if this tool only comes with a later version of GRASS,
or is it possible that I missed a build step.

v.generalize is available in GRASS >= 6.3.0. BTW, GRASS 6.2.3 is
pretty old. Try the last RC of GRASS 6.4.0 (RC4).

Regards, Martin

–
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa

4

Hi All,

Got Version 6.4 working last night and started to experiment with v.generalize. I’m using it on a group of polygons that represent the Hawaiian islands and noticed some interesting behavior. In other systems, I would expect these features to be treated at “multipolygons”, however in GRASS I see that I have the option of specifying point, line, boundary, or area. I’m not exactly sure what the difference between boundary and area is, but it does seem to make a difference in the v.generalize output which of them I choose. Can someone clarify for me how these geometry types affect the operation v.generalize?

Thanks,

Roger

On Tue, Apr 14, 2009 at 4:23 PM, Roger André <randre@gmail.com> wrote:

Hi Martin,

Thanks for the info, I’ll get 6.4 installed tonight.

Roger

On Tue, Apr 14, 2009 at 3:23 PM, Martin Landa <landa.martin@gmail.com> wrote:

Hi,

2009/4/14 Roger André <randre@gmail.com>:

Sorry for the newbie question, but I just finished getting GRASS 6.23 built
last night and am using it for the first time today. I’ve gotten a new
location created, and a shapefile imported, and now I would like to simplify
the geometry. Unfortunately, it appears that v.generalize is missing.

Can someone tell me if this tool only comes with a later version of GRASS,
or is it possible that I missed a build step.

v.generalize is available in GRASS >= 6.3.0. BTW, GRASS 6.2.3 is
pretty old. Try the last RC of GRASS 6.4.0 (RC4).

Regards, Martin

–
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa

5

2009/4/15 Roger André <randre@gmail.com>:

Got Version 6.4 working last night and started to experiment with
v.generalize. I'm using it on a group of polygons that represent the
Hawaiian islands and noticed some interesting behavior. In other systems, I
would expect these features to be treated at "multipolygons", however in
GRASS I see that I have the option of specifying point, line, boundary, or
area. I'm not exactly sure what the difference between boundary and area
is, but it does seem to make a difference in the v.generalize output which
of them I choose. Can someone clarify for me how these geometry types
affect the operation v.generalize?

http://grass.osgeo.org/grass64/manuals/html64_user/vectorintro.html

-> Vector model and topology

M.

--
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa

6

Excellent, thank you. Am I correct then in assuming that I can treat all of my multipolygon data as type=boundary for the purposes of using v.generalize? The end goal is to buffer the geometry and then export it back out as a shapefile.

Thanks again for your assistance.

Roger

On Wed, Apr 15, 2009 at 10:13 AM, Martin Landa <landa.martin@gmail.com> wrote:

2009/4/15 Roger André <randre@gmail.com>:

Got Version 6.4 working last night and started to experiment with
v.generalize. I’m using it on a group of polygons that represent the
Hawaiian islands and noticed some interesting behavior. In other systems, I
would expect these features to be treated at “multipolygons”, however in
GRASS I see that I have the option of specifying point, line, boundary, or
area. I’m not exactly sure what the difference between boundary and area
is, but it does seem to make a difference in the v.generalize output which
of them I choose. Can someone clarify for me how these geometry types
affect the operation v.generalize?

http://grass.osgeo.org/grass64/manuals/html64_user/vectorintro.html

→ Vector model and topology

M.

–

Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa