[GRASS-user] Checking if a point (X, Y) is inside the polygons of a shape file using command line

GRASS GRASS user
1

Dear friends,

I have a shape file, with some polygons. (I have imported it as vector layer.)

I have a point, expressed as X,Y coordinates (Easting,Northing).

I want to know if the point is inside any of the polygons in the shape file.

Is there a command I can use?

I would rather use command line, because I have many points, really. I would
like to find a way to do it from the command line, so that I can write a
routine to extract each point and check if it is inside the polygons.

I can rephrase the question, if it is not clear.

I am not very experienced with Grass but would like to substitute ArcGIS, that
we are using now.

Best regards
--
Corrado Topi

Global Climate Change & Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk

2

Corrado,

You can do this with v.select:

v.select ainput=input_points binput=input_polygon out=output_points

Cheers,
John

On Mar 3, 2008, at 8:02 AM, Corrado wrote:

Dear friends,

I have a shape file, with some polygons. (I have imported it as vector layer.)

I have a point, expressed as X,Y coordinates (Easting,Northing).

I want to know if the point is inside any of the polygons in the shape file.

Is there a command I can use?

I would rather use command line, because I have many points, really. I would
like to find a way to do it from the command line, so that I can write a
routine to extract each point and check if it is inside the polygons.

I can rephrase the question, if it is not clear.

I am not very experienced with Grass but would like to substitute ArcGIS, that
we are using now.

Best regards
--
Corrado Topi

Global Climate Change & Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk
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