Re: [GRASS-user] Interpolation on a Grid
On 04/04/2010 04:39 AM, H.S.Rai wrote: On Wed, Feb 18, 2009 at 4:02 AM, Hamishhamis...@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=2.50 dmax=12.50 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 ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Interpolation on a Grid
On Wed, Feb 18, 2009 at 4:02 AM, Hamish hamis...@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. 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. -- H.S.Rai ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Interpolation on a Grid
Frank Aragona 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. Any suggestions as to how best
to do this?
Hamish:
depending on how many input points you have either:
v.in.ascii, g.region res=100, v.surf.rst
or for massive datasets (1-3 million points):
g.region res=100, r.in.xyz, r.to.vect, v.surf.rst
choice of method and {r|v}.surf.* interpolation module are subject to
nature of data personal preference. see also r.surf.nnbathy in wiki
addons. the modules' manual pages should help you decide.
Frank wrote:
But I'd like the interpolated surface to be a set of
100' x 100' vector grids, each 100 x 100 square with
a discrete elevation value. Is this possible?
after import binning as a raster use v.mkgrid to make your 100x100 grid,
then use v.what.rast or v.rast.stats to give each square an elevation
value. or maybe r.to.vect is easier?
Hamish
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[GRASS-user] Interpolation on a Grid
List, 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. Any suggestions as to how best to do this? -- Frank Aragona ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
