[GRASS5] Built-in vector documentation extended

GRASS GIS GRASS GIS developer
1

Hi,

I have extended the vector overview document in
6.1-CVS, find also here:

http://grass.itc.it/grass61/manuals/html61_user/vectorintro.html

While it covers most modules, each now in a thematic
context, it may be fine tuned, improved.
Text pieces welcome (preferably CVS patches).

The idea is to give a short overview.

Currently the page is even W3 conformant :slight_smile:

Cheers

Markus

2

Markus,

This is very helpful. It will make learning GRASS vector architecture much
easier for people.

Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton

From: Markus Neteler <neteler@itc.it>
Date: Thu, 16 Mar 2006 22:35:22 +0100
To: grass developers list <grass5@grass.itc.it>
Cc: GRASS user list <grasslist@baylor.edu>
Subject: [GRASS5] Built-in vector documentation extended

Hi,

I have extended the vector overview document in
6.1-CVS, find also here:

http://grass.itc.it/grass61/manuals/html61_user/vectorintro.html

While it covers most modules, each now in a thematic
context, it may be fine tuned, improved.
Text pieces welcome (preferably CVS patches).

The idea is to give a short overview.

Currently the page is even W3 conformant :slight_smile:

Cheers

Markus

3

Michael,

This is very helpful and answers many questions I have about the new vector format, especially points. I do want to confirm my understanding from "Vector data processing in GRASS GIS" (please pardon my being obtuse). So…

In order to get a Postgres table consisting of point coordinates and various attributes to import into my lat-long location using v.in.db, I had to put a "1" in the field for the "category column name (string required)"; when I put "lid" in the field, I got an error saying the type was not an integer. It seems GRASS is expecting a string for the field name that has integer as its type. My problem is that none of my fields meet this requirement for the key field, the only column that does, "lid", has type string.

Now, my question is, for 5030 records, how do I add an integer key field? My guess is that I would have to write a script that (1) created a new column (type integer) for the Postgres table and (2) looped, sequentially filling the new field for each record with a unique integer value — or I could drop the table, and do all of this outside of the Postgres/GRASS environment and reload the table. The problem I have with doing either is that the table design is not my own and is controlled by 'outsiders'.

Regards,
Tom

Michael Barton wrote:

Markus,

This is very helpful. It will make learning GRASS vector architecture much
easier for people.

Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton

From: Markus Neteler <neteler@itc.it>
Date: Thu, 16 Mar 2006 22:35:22 +0100
To: grass developers list <grass5@grass.itc.it>
Cc: GRASS user list <grasslist@baylor.edu>
Subject: [GRASS5] Built-in vector documentation extended

Hi,

I have extended the vector overview document in
6.1-CVS, find also here:

http://grass.itc.it/grass61/manuals/html61_user/vectorintro.html

While it covers most modules, each now in a thematic
context, it may be fine tuned, improved.
Text pieces welcome (preferably CVS patches).

The idea is to give a short overview.

Currently the page is even W3 conformant :slight_smile:

Cheers

Markus

_______________________________________________
grass5 mailing list
grass5@grass.itc.it
http://grass.itc.it/mailman/listinfo/grass5

--
Thomas E Adams
National Weather Service
Ohio River Forecast Center
1901 South State Route 134
Wilmington, OH 45177

EMAIL: thomas.adams@noaa.gov

VOICE: 937-383-0528
FAX: 937-383-0033

4

Thomas,

See below.

Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton

From: Thomas Adams <Thomas.Adams@noaa.gov>
Date: Fri, 17 Mar 2006 12:37:20 -0500
To: Michael Barton <michael.barton@asu.edu>
Cc: Markus Neteler <neteler@itc.it>, grass developers list
<grass5@grass.itc.it>, Multiple recipients of list <grasslist@baylor.edu>
Subject: Re: [GRASS5] Built-in vector documentation extended

Michael,

This is very helpful and answers many questions I have about the new
vector format, especially points. I do want to confirm my understanding
from "Vector data processing in GRASS GIS" (please pardon my being
obtuse). SoÅ 

In order to get a Postgres table consisting of point coordinates and
various attributes to import into my lat-long location using v.in.db, I
had to put a "1" in the field for the "category column name (string
required)"; when I put "lid" in the field, I got an error saying the
type was not an integer. It seems GRASS is expecting a string for the
field name that has integer as its type. My problem is that none of my
fields meet this requirement for the key field, the only column that
does, "lid", has type string.

The GRASS vector key field ("category") MUST be an integer. The matching key
field in your attribute table must also be integer to make a join.

Now, my question is, for 5030 records, how do I add an integer key
field? My guess is that I would have to write a script that (1) created
a new column (type integer) for the Postgres table and (2) looped,
sequentially filling the new field for each record with a unique integer
value ‹ or I could drop the table, and do all of this outside of the
Postgres/GRASS environment and reload the table. The problem I have with
doing either is that the table design is not my own and is controlled by
'outsiders'.

Use v.category to do this in GRASS.

Michael

Regards,
Tom

Michael Barton wrote:

Markus,

This is very helpful. It will make learning GRASS vector architecture much
easier for people.

Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton

From: Markus Neteler <neteler@itc.it>
Date: Thu, 16 Mar 2006 22:35:22 +0100
To: grass developers list <grass5@grass.itc.it>
Cc: GRASS user list <grasslist@baylor.edu>
Subject: [GRASS5] Built-in vector documentation extended

Hi,

I have extended the vector overview document in
6.1-CVS, find also here:

http://grass.itc.it/grass61/manuals/html61_user/vectorintro.html

While it covers most modules, each now in a thematic
context, it may be fine tuned, improved.
Text pieces welcome (preferably CVS patches).

The idea is to give a short overview.

Currently the page is even W3 conformant :slight_smile:

Cheers

Markus

_______________________________________________
grass5 mailing list
grass5@grass.itc.it
http://grass.itc.it/mailman/listinfo/grass5

--
Thomas E Adams
National Weather Service
Ohio River Forecast Center
1901 South State Route 134
Wilmington, OH 45177

EMAIL: thomas.adams@noaa.gov

VOICE: 937-383-0528
FAX: 937-383-0033