If you are talking about constructing a surface, have you looked at Regrid
or Connect? Input is data on 2d coordinates (positions). Output has
connections. Regrid has new positions. Connect preserves the original
positions. Rubbersheet can operate on either output doing a linear mapping
of the data to a 3d coordinate. Here's a very old paper that describes an
application of these ideas:
http://www.research.ibm.com/dx/proceedings/peru/index.htm or a couple of
MPEGs of the results:
http://www.research.ibm.com/people/l/lloydt/rainfall.mpg and
http://www.research.ibm.com/people/l/lloydt/peru_video.mpg
If memory serves, GMT had additional tools along these lines. You would
have to evaluate which methods would be more suitable.
If you talking about determining the value at a point on the surface,
interactively, have you looked at Probe or Pick?
Brent Wood <[EMAIL PROTECTED]>@opendx.watson.ibm.com on 11/19/2002 04:16:24
PM
Please respond to [email protected]
Sent by: [EMAIL PROTECTED]
To: Jens Fernandez-Vega <[EMAIL PROTECTED]>
cc: Opendx-Users <[email protected]>
Subject: Re: [opendx-users] Interpolating points
On Tue, 19 Nov 2002, Jens Fernandez-Vega wrote:
I suggest you install GMT (Generic Mapping Tools). I use this in
conjunction with OpenDX quite usefully.
GMT uses netCDF grids as binary surface models.
the command
xyz2grd <file.xyz> <assorted parameters>
will build a surface model representing your data, there are other
commands to do this as well (including surface, etc) to give control over
various aspects of the model.
the command
echo "$X $Y" | grdtrack <parameters>
or
cat <file of x y values> | grdtrack <parameters>
will return the interpolated value(s) at each X y location from the grid.
I'm using GMT to derive grids which are then used in OpenDX. GMT is also
Open Source.
> I managed to create a Rubbersheet with the dx data, autocolor and find
the
> gradient of the surface. But now I would like to input the X and Y
> coordinates of some points and find out the corresponding Z value. Is
this
> possible?
>
> If somebody could point me to the past emails that could help or give
some
> hints or suggestions, it would be great.
Not a OpenDX based solution, but it will easily do what you want.
Cheers
Brent Wood
