Prev: Finding a root
Next: how to ignore some sampling points
From: Chris on 9 Jul 2010 08:06
I am trying to create an evenly spaced mesh of Lat, Long and then an observation at each point. I have 123 points that are scattered in an excel document. What I am trying to do is create a 123x123 mesh of these points. So each point has an observation but I the mesh I want to create is evenly spaced coordinates with an observation at each increment. How would I go about doing this? Thanks
From: Steven Lord on 9 Jul 2010 09:15

"Chris " <chris.veinot(a)hotmail.com> wrote in message
news:i173c2$hlh$1(a)fred.mathworks.com...
>I am trying to create an evenly spaced mesh of Lat, Long and then an
>observation at each point. I have 123 points that are scattered in an
>excel document. What I am trying to do is create a 123x123 mesh of these
>points. So each point has an observation but I the mesh I want to create
>is evenly spaced coordinates with an observation at each increment. How
>would I go about doing this? Thanks

Look at TRISCATTERDINTERP:

http://www.mathworks.com/access/helpdesk/help/techdoc/ref/triscatteredinterpclass.html

or GRIDDATA if your version predates the introduction of this object:

http://www.mathworks.com/access/helpdesk/help/techdoc/ref/griddata.html

but keep in mind that depending on how your data is scattered you may not
have enough information to create the mesh (for instance, if your points
were all on a straight line, you wouldn't have any information about the
behavior of the "function" underlying your observed quantity for points off
the line) and/or your mesh may contain NaNs if one or more of the points in
your grid are outside the convex hull of your data.

--
Steve Lord
slord(a)mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ
To contact Technical Support use the Contact Us link on
http://www.mathworks.com


 | 
Pages: 1
Prev: Finding a root
Next: how to ignore some sampling points