[GRASS-user] finding bounding box of polygons

[Gerald Nelson]

The following command
 ogrinfo -al -where 'CNTRY_NAME=GERMANY' SubNationalboundaries.shp

gets me all the attributes for Germany in the shapefile. This includes a POLYGON attribute for each subnational unit with a bunch of lat-long values, but does not, as far as I can tell, get me a bounding box. 

Any other suggestions appreciated.

Jerry

---- Original message ----
>Date: Sun, 30 Sep 2007 16:56:25 -0700
>From: "John C. Tull" <john.tull at wildnevada.org>  
>Subject: Re: [GRASS-user] finding bounding box of polygons  
>To: Jerry Nelson <gnelson at uiuc.edu>
>
>You can run a query on ogrinfo with -where, but I am not certain if  
>the bounds will reflect the query. I would suspect as much.
>
>http://www.gdal.org/ogr/ogrinfo.html
>
>Cheers,
>John
>
>On Sep 30, 2007, at 3:19 PM, Jerry Nelson wrote:
>
>> What I'm trying to do is get the bounding boxes around each country  
>> in the
>> world, so I can create a region file for each. This would make doing
>> graphics by country much easier. For example, we have constructed a  
>> raster
>> at 1 km resolution of the number of amphibian species ranges at each
>> location for the whole world. There are times when I just want, say  
>> the
>> counts in India. We have a nice little script that generates a png
>> automatically based on a region file. It would be nice to have such  
>> a file
>> for each country in the world.
>>
>> If I read your example correctly, ogrinfo gives me the box around  
>> the entire
>> shapefile, not individual polygons. I suppose an alternative would  
>> be to
>> somehow export each country polygon as a separate shapefile and get  
>> the
>> region of that.
>>
>> Any tips appreciated.
>> Thanks, Jerry
>>
>> -----Original Message-----
>> From: Jose Gomez-Dans [mailto:jgomezdans at gmail.com]
>> Sent: Thursday, September 27, 2007 4:59 PM
>> To: Jerry Nelson
>> Cc: grassuser at grass.itc.it
>> Subject: Re: [GRASS-user] finding bounding box of polygons
>>
>> Hi,
>>
>> On 9/27/07, Jerry Nelson <gnelson at uiuc.edu> wrote:
>>> I'd like to construct a list of the bounding box coordinates for  
>>> all the
>>> polygons in a vector file. I could find nothing in the manual that  
>>> seemed
>> to
>>> do that. Any tips appreciated.
>>
>> Not a GRASS-centric response :), but if it is just a box you're after,
>> you can probably use ogrinfo for this, as it gives you the Extent of
>> your file. As an example, using it with the world.shp Shapefile
>> results in:
>> $ ogrinfo -so python/world.shp world
>> INFO: Open of `python/world.shp'
>>       using driver `ESRI Shapefile' successful.
>>
>> Layer name: world
>> Geometry: Polygon
>> Feature Count: 244
>> Extent: (-180.000000, -89.900000) - (180.000000, 83.674733)
>> Layer SRS WKT:
>> (unknown)
>> NAME: String (40.0)
>> CAPITAL: String (64.0)
>> APPROX: Real (15.0)
>> AREA: Real (20.15)
>> SOURCETHM: String (16.0)
>>
>> Hope that helps
>>
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>
Gerald Nelson
Professor, Dept. of Agricultural and Consumer Economics
University of Illinois, Urbana-Champaign
office: 217-333-6465 
cell: 217-390-7888
315 Mumford Hall
1301 W. Gregory
Urbana, IL 61801