[GRASSLIST:5504] Restricting data summary to a specific area.

GRASS GRASS user
1

I have a map of parcel data in vector form and would like to restrict
my queries to a certain area. For example, in Arc View, I was able to
draw an outline around my area of interest and then extract information
for only those parcels contained in that area. Is there similar
functionality in GRASS? I don't have the money to buy ArcView, so that
isn't an option, but I really need to be able to do this.

I would really appreciate it if someone could point me in the right
direction.

Thanks,
Jason

2

OK, I have managed to use v.digit to draw the proper boundaries around
my area, but I have run into another problem. My intent was to use the
new vector file I created to cut the old vector file down to size. Well,
it isn't working. The use of v.cutter seems to work - at least it does
something - but when I try to display the new layer - nothing. Any
suggestions?

Jason

On Fri, Feb 07, 2003 at 03:01:57PM -0500, Jason Morgan wrote:

I have a map of parcel data in vector form and would like to restrict
my queries to a certain area. For example, in Arc View, I was able to
draw an outline around my area of interest and then extract information
for only those parcels contained in that area. Is there similar
functionality in GRASS? I don't have the money to buy ArcView, so that
isn't an option, but I really need to be able to do this.

I would really appreciate it if someone could point me in the right
direction.

Thanks,
Jason

3

Hi to all
I need a quick help.....
I have this site file (in attach) , where the column starting with % is the
column of elevation...

I have to transform this file in vector format but using s.to.vect, I obtain
wrong results (I think because it use category values (#*) and not
attributes)

I would obtain a vector point file with elevations as categories (to patch it
with a vector contour file and interpolate the result)

I'm becoming crazy....
can someone help me???

Thank you very much???

ivan

--
Ivan Marchesini
University of Perugia
Italy

(attachments)

punti (7.89 KB)

4

On Mon, Feb 10, 2003 at 07:00:39PM +0100, Ivan Marchesini wrote:

Hi to all
I need a quick help.....
I have this site file (in attach) , where the column starting with % is the
column of elevation...

I have to transform this file in vector format but using s.to.vect, I obtain
wrong results (I think because it use category values (#*) and not
attributes)

GRASS~> s.to.vect input=<name> output=<name> cat=decimal,1

--
echo ">gra.fcw@2ztr< eryyvZ .T pveR" | rot13 | reverse

5

Hi to all
I have another question
I have to export a vector grass file in dxf format...
grass exports ascii-dxf but autocad is not able to open it....
How can I export or transform ascii-dxf in binary dxf???
thank you very much!!!
Ivan

--
Ivan Marchesini
University of Perugia
Italy

6

Thank you very much!!!!!
bye

Ivan

Alle 03:38, martedì 11 febbraio 2003, Eric G. Miller ha scritto:

On Mon, Feb 10, 2003 at 07:00:39PM +0100, Ivan Marchesini wrote:
> Hi to all
> I need a quick help.....
> I have this site file (in attach) , where the column starting with % is
> the column of elevation...
>
> I have to transform this file in vector format but using s.to.vect, I
> obtain wrong results (I think because it use category values (#*) and not
> attributes)

GRASS~> s.to.vect input=<name> output=<name> cat=decimal,1

--
Ivan Marchesini
University of Perugia
Italy

7

I have to export a vector grass file in dxf format...
grass exports ascii-dxf but autocad is not able to open it....
How can I export or transform ascii-dxf in binary dxf???

see if qCad can open it:
http://www.qcad.org
"QCad is a free open-source 2D CAD system for Linux, various Unices and Windows."

and then resave whatever layers you need..

maybe in autocad "open as filetype" for an older autocad version? (8.x) ??

8

Could it be a problem with returns on different platforms? DXF is just a text file, but the text which GRASS exports will have unix returns (I suspect) while AutoCAD may expect a text file with Windows returns. You might open the dxf file in a text editor (I'm using a Mac and use BBEdit), check what kind of returns it has, and change to Windows if necessary; that might solve it.

I use Microstation on a Mac, and export dxf from that to import into GRASS; but it doesn't work if I don't open the dxf file and convert it to a unix text file first.

Nick Cahill

On Tuesday, February 11, 2003, at 09:39 PM, H. Bowman wrote:

I have to export a vector grass file in dxf format...
grass exports ascii-dxf but autocad is not able to open it....
How can I export or transform ascii-dxf in binary dxf???

see if qCad can open it:
http://www.qcad.org
"QCad is a free open-source 2D CAD system for Linux, various Unices and Windows."

and then resave whatever layers you need..

maybe in autocad "open as filetype" for an older autocad version? (8.x) ??