[GRASSLIST:5540] Re: v.mkgrid extract grid sections

[Radim Blazek]

Use v.extract type=area

Radim

Dylan Beaudette wrote:
> On Wednesday 26 January 2005 06:09 pm, Hamish wrote:
> 
>>>I have used v.mkgrid (GRASS6-CVS) in the past to make vector grids,
>>>and all  has been well.
>>
>>..
>>
>>
>>>However, this morning I tried to extract a single square from the
>>>output from  v.mkgrid, and was only able to get either a single
>>>centroid (almost correct),  or the entire boundary (not good). Since
>>>the boundaries do not have CATs,  there is no way for me to extract a
>>>single boundary...
>>
>>..
>>
>>
>>>Any ideas?
>>
>>what about
>>
>>  v.category type=boundary option=add
>>
>>to add category numbers to the boundaries?
>>
> 
> 
> Thanks! ... this gives the boundaries CATs... but for some reason, each grid 
> square is made up of about 8 line segments (3 for top and bottom lines, 1 for 
> each vertical line)... 
> 
> My hope is that i can make each grid "cell" into a discreet polygon, that can 
> be used to set the region -- i.e. so that i can accurately subsample a larger 
> map.
> 
> thanks!
>