[GRASSLIST:7196] v.out.ascii format question

GRASS GRASS user
1

Hey people,

I'm trying to figure out exactly what the v.out.ascii
(format=standard) outputs. The v.out.ascii or
v.in.ascii help pages don't directly help - they
don't handle the things that come after the
coordinates.

I seem to have a few lines without coordinates in
my data (spearfish60, actually), which I'll just assume
is allowed, but more interestingly, I can't make full
sense out of what seem to be category lines after
the coordinates of each feature. What do the two
numbers mean? Perhaps id (of what?) and category?
What happens when there is more than one line of these?

Relatedly, if those are categories I don't know
what to make of the "v.out.ascii does not copy
the dig_cats [...]" comment in the v.out.ascii
documentation. (I use grass 6.0.0, by the way)

Basically I'd like to know what the output format
is, exactly. A little 'why' would be nice too:)

Thanks in advance,
--Bart Alewijnse

2

I'm trying to figure out exactly what the v.out.ascii
(format=standard) outputs. The v.out.ascii or
v.in.ascii help pages don't directly help - they
don't handle the things that come after the
coordinates.

I seem to have a few lines without coordinates in
my data (spearfish60, actually), which I'll just assume
is allowed, but more interestingly, I can't make full
sense out of what seem to be category lines after
the coordinates of each feature. What do the two
numbers mean? Perhaps id (of what?) and category?
What happens when there is more than one line of these?

Relatedly, if those are categories I don't know
what to make of the "v.out.ascii does not copy
the dig_cats [...]" comment in the v.out.ascii
documentation. (I use grass 6.0.0, by the way)

Basically I'd like to know what the output format
is, exactly. A little 'why' would be nice too:)

The vector ascii format is quickly described on the v.in.ascii help
page and that links to the format specification:

http://grass.ibiblio.org/grass61/manuals/html61_user/v.in.ascii.html
http://freegis.org/cgi-bin/viewcvs.cgi/~checkout~/grass6/doc/vector/vector.html#ascii

Read the specification.
  (note there's an error there: Y X was changed to X Y)

see the v.in.garmin script in GRASS 6 for a working example of using
GRASS ASCII vector files with categories.

Hamish

3

On 6/17/05, Hamish <hamish_nospam@yahoo.com> wrote:

> I'm trying to figure out exactly what the v.out.ascii
> (format=standard) outputs. The v.out.ascii or
> v.in.ascii help pages don't directly help - they
> don't handle the things that come after the
> coordinates.
>
> I seem to have a few lines without coordinates in
> my data (spearfish60, actually), which I'll just assume
> is allowed, but more interestingly, I can't make full
> sense out of what seem to be category lines after
> the coordinates of each feature. What do the two
> numbers mean? Perhaps id (of what?) and category?
> What happens when there is more than one line of these?
>
> Relatedly, if those are categories I don't know
> what to make of the "v.out.ascii does not copy
> the dig_cats [...]" comment in the v.out.ascii
> documentation. (I use grass 6.0.0, by the way)
>
> Basically I'd like to know what the output format
> is, exactly. A little 'why' would be nice too:)

The vector ascii format is quickly described on the v.in.ascii help
page and that links to the format specification:

http://grass.ibiblio.org/grass61/manuals/html61_user/v.in.ascii.html
http://freegis.org/cgi-bin/viewcvs.cgi/~checkout~/grass6/doc/vector/vector.html#ascii

Okay, thanks...
But what are the field ID's about? Once exported I doubt
they're useful for database reference. I don't suppose there's
any real comparability between fields in different features in
the same map? Are they just a dummy enumeration, or more?

Thanks,
--Bart