interp2 problem: input grid is not a valid meshgrid

I would like to interpolate, but I keep on getting the message: Error using interp2>makegriddedinterp (line 220) Input grid is not a valid MESHGRID.
Below is a simplified version of my data. Does anyone know how to solve this? Thank you!
Y=[30 29 27 20;32 31 29 22;35 34 32 25]
X=[0 2 5 10;0 2 5 10;0 2 5 10]
V=[1 2 3.5 4 ; 1.2 2.3 3.8 4.8; 1.4 2.6 4.2 5]
Yq=30
Xq=4

1 comentario

dpb
dpb el 13 de Jun. de 2014
Editada: dpb el 13 de Jun. de 2014
Well, show what you did that raised the error and what you want. The round, translucent orb is somewhat murky today...
ADDENDUM
OK, I didn't look at the posted data closely enough first time -- from the doc for interp2 one finds--
... All the interpolation methods require that X and Y be monotonic and plaid (as if they were created using MESHGRID).
Your X data are monotonic ok, but they're not regular (plaid) as must be.

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Respuestas (1)

dpb
dpb el 13 de Jun. de 2014
Editada: dpb el 13 de Jun. de 2014
As noted in the comment, your data set doesn't meet the requirements of *interp2* of a uniform mesh in both directions. Use *TriScatteredInterp* instead...
>> F = TriScatteredInterp(X(:),Y(:),V(:));
>> F(Xq,Yq)
ans =
3.3444
>>

4 comentarios

Matt J
Matt J el 13 de Jun. de 2014
Editada: Matt J el 13 de Jun. de 2014
Or use scatteredInterpolant.
>> which scatteredInterpolant
'scatteredInterpolant' not found.
>>
Matt J
Matt J el 13 de Jun. de 2014
Editada: Matt J el 13 de Jun. de 2014
Time to upgrade! TriScatteredInterp will be removed eventually, see
dpb
dpb el 13 de Jun. de 2014
R2012b has brung my machine to about all it can do even after adding all the memory it can hold. Since I've retired from consulting, not much incentive to spend $$ on all the things I've become accustomed to besides Matlab so I'll probably just stand pat until the machine dies. Then it'll be a hard decision...

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Preguntada:

Kim
el 13 de Jun. de 2014

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dpb
el 13 de Jun. de 2014

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