[GRASS-user] Interpolation on a Grid

[Micha Silver]

On 04/04/2010 04:39 AM, H.S.Rai wrote:
> On Wed, Feb 18, 2009 at 4:02 AM, Hamish<hamish_b at yahoo.com>  wrote:
>    
>>      
>>> I'd like to do an interpolation of xyz data points that
>>> I have, and put the interpolated data on 100' x 100'
>>> grid.  So that each 100' x 100' square has an
>>> associated elevation value.
>>>        
>> depending on how many input points you have either:
>>   v.in.ascii, g.region res=100, v.surf.rst
>>      
> Unable to achieve desired result. I has nice contour maps using
> following commands:
>
> ----------
> v.in.ascii -z z=3  --overwrite input=survey.txt output=fieldData
> v.build map=fieldData
> g.region vect=fieldData
> v.surf.rst input=fieldData layer=0 elev=DTM1
> r.contour input=DTM1 output=contourVec1 step=100 cut=0
> r.contour input=DTM1 output=contourVec2 step=20 cut=0
> d.mon x0
> d.rast map=DTM1
> d.vect map=contourVec1 display=shape,zcoor
> d.vect map=contourVec2 display=shape
> --------
>
> But to have elevation on grid could not figure out parameters for
> v.surf.rst command. In GUI could not find input option.
>
>    
Here's an example that I've used (copied from r.info). The original 
point layer is more or less a grid of points at 40X40 meter separation.

v.surf.rst input="eyv_pts" layer=0 elev="eyv_dem" tension=40. segmax=40 
npmin=300 dmin=2.500000 dmax=12.500000 zmult=1.0

HTH,
Micha
> Can you help me by giving complete commands with options and values as
> per above example to have shown elevation at regular grid. I started
> with resolution of 1 for a size of 100x100, and for grid I can have
> resolution of 20.
>
> Using GRASS 6.4.0RC5 on Ubuntu 9.10
>
> Mine data  is small.
>
> Thanks in advance.
>
>    


-- 
Micha Silver
http://www.surfaces.co.il/
Arava Development Co.  +972-52-3665918