[GRASSLIST:3379] Removing boundaries on vector maps

GRASS GRASS user
1

Hello,
I have a number of vector maps, each representing stream paths over a USGS
7.5' quad. The boundaries of the quads are present on each map. Is there a
scriptable way to remove those boundaries before or after patching the maps ?
Thanks for any hint

--
Soil & Water Laboratory
Dept. of Biological & Environmental Engineering
Cornell University
ITHACA, NY 14853
Tel: (607)255.2463

2

I’m in the same predicament. I’ve got a series of 7.5min DLGs (hydro, transpostation, boundaries) that I have v.patch’ed together and am now looking for a way to remove the duplicate border vectors.

According to the 5.7 manual entry for v.patch:
"Any vectors that are duplicated among the maps being patched together (e.g., border lines) will have to be edited or removed after v.patch is run. Such editing can be done automatically using v.clean (tool=svtlx). "

I received undesirable results when running v.clean tool=rmdupl. After running the command many boundary vectors remained and several vctors depicting actual features were removed. It may be that if the boundary lines were not set as a particular category they may have to be removed manualy using v.digit.

Can anyone here shed some light on the subject?

Thanks,

Luis.

SWlab swlab@cornell.edu
Sent by: owner-GRASSLIST@baylor.edu

05/09/04 02:57 PM
Please respond to swlab
To: grasslist@baylor.edu
cc:
Subject: [GRASSLIST:3379] Removing boundaries on vector maps

Hello,
I have a number of vector maps, each representing stream paths over a USGS
7.5' quad. The boundaries of the quads are present on each map. Is there a
scriptable way to remove those boundaries before or after patching the maps ?
Thanks for any hint

--
Soil & Water Laboratory
Dept. of Biological & Environmental Engineering
Cornell University
ITHACA, NY 14853
Tel: (607)255.2463

3

> I'm in the same predicament. I've got a series of 7.5min DLGs
> (hydro, transpostation, boundaries) that I have v.patch'ed together
> and am now looking for a way to remove the duplicate border vectors.
>
> According to the 5.7 manual entry for v.patch:
> "Any vectors that are duplicated among the maps being patched
> together (e.g., border lines) will have to be edited or removed
> after v.patch is run. Such editing can be done automatically using
> v.clean(tool=svtlx). "I received undesirable results when running
> v.clean tool=rmdupl. After running the command many boundary
> vectors remained and several vctors depicting actual features were
> removed. It may be that if the boundary lines were not set as a
> particular category they may have to be removed manualy using
> v.digit.

I have a number of vector maps, each representing stream paths over a
USGS 7.5' quad. The boundaries of the quads are present on each map.
Is there a scriptable way to remove those boundaries before or after
patching the

[GRASS 5.7]
This isn't a proper solution, but you might try some combination of:

g.region vect=...
v.in.region
v.select (or v.overlay) to get rid of common features (ie the border)

Hamish

4

On Monday 10 May 2004 22:15, Luis E Menoyo wrote:

I'm in the same predicament. I've got a series of 7.5min DLGs (hydro,
transpostation, boundaries) that I have v.patch'ed together and am now
looking for a way to remove the duplicate border vectors.

According to the 5.7 manual entry for v.patch:
"Any vectors that are duplicated among the maps being patched together
(e.g., border lines) will have to be edited or removed after v.patch is
run. Such editing can be done automatically using v.clean (tool=svtlx). "
I received undesirable results when running v.clean tool=rmdupl. After
running the command many boundary vectors remained and several vctors
depicting actual features were removed.

v.clean tool=rmdupl should remove only one of duplicate features.
'break' tool should be usually run before 'rmdupl'.
Can you extract (v.in.region, v.select) a part of data where 'actual features
were removed' by repeated 'rmdupl' and send it to me (coor file)?

It may be that if the boundary
lines were not set as a particular category they may have to be removed
manualy using v.digit.
Can anyone here shed some light on the subject?

If I understand it well, you want remove the boundary of quad from all
patched maps. This should be done before v.patch. Does not exist
any attribute, which can distinguish the boundary from lines?
How the data was imported, can you send a link to the data on the Web?

Radim

Thanks,
Luis.

SWlab <swlab@cornell.edu>
Sent by: owner-GRASSLIST@baylor.edu
05/09/04 02:57 PM
Please respond to swlab

        To: <grasslist@baylor.edu>
        cc:
        Subject: [GRASSLIST:3379] Removing boundaries on vector
maps

Hello,
I have a number of vector maps, each representing stream paths over a USGS

7.5' quad. The boundaries of the quads are present on each map. Is there a

scriptable way to remove those boundaries before or after patching the
maps ?
Thanks for any hint

5

I have imported SWlab's data, it seems that all desired lines have
major1 > 0
and the frame has
major1 = -99999
so
v.extract input=u41 output=u41_clean where='major1 > 0'
should do what you want.

Radim

On Monday 10 May 2004 22:15, Luis E Menoyo wrote:

I'm in the same predicament. I've got a series of 7.5min DLGs (hydro,
transpostation, boundaries) that I have v.patch'ed together and am now
looking for a way to remove the duplicate border vectors.

According to the 5.7 manual entry for v.patch:
"Any vectors that are duplicated among the maps being patched together
(e.g., border lines) will have to be edited or removed after v.patch is
run. Such editing can be done automatically using v.clean (tool=svtlx). "
I received undesirable results when running v.clean tool=rmdupl. After
running the command many boundary vectors remained and several vctors
depicting actual features were removed. It may be that if the boundary
lines were not set as a particular category they may have to be removed
manualy using v.digit.
Can anyone here shed some light on the subject?
Thanks,
Luis.

SWlab <swlab@cornell.edu>
Sent by: owner-GRASSLIST@baylor.edu
05/09/04 02:57 PM
Please respond to swlab

        To: <grasslist@baylor.edu>
        cc:
        Subject: [GRASSLIST:3379] Removing boundaries on vector
maps

Hello,
I have a number of vector maps, each representing stream paths over a USGS

7.5' quad. The boundaries of the quads are present on each map. Is there a

scriptable way to remove those boundaries before or after patching the
maps ?
Thanks for any hint