Problem with Interpolation function involving 2 variables

Question

Sangani Prithvi 2021-9-2

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1445199-problem-with-interpolation-function-involving-2-variables

评论： Walter Roberson 2021-9-2

xyz.xlsx

Hi,

I've tried to use the interp2 function to interpolate 'Zq' coordinates from the raw 'X,Y,Z' data attached in the file here. Interpolation is carried for Xq = -60:60 and Yq = -160:160.

I'm getting an error of this kind when I run the program.

" Error using griddedInterpolant

The grid vectors must be strictly monotonically increasing"

Is there a way to find the interpolation for such data?

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KSSV 2021-9-2

Use meshgrid for Xq and Yq.

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Answer 1

Walter Roberson 2021-9-2

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1445199-problem-with-interpolation-function-involving-2-variables#answer_779339

在 MATLAB Online 中打开

filename = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/727494/xyz.xlsx';

T = readtable(filename);

F = scatteredInterpolant(T.X, T.Y, T.Z);

Xq = -60:60;

Yq = -160:160;

[XQ, YQ] = meshgrid(Xq, Yq);

ZQ = F(XQ, YQ);

surf(XQ, YQ, ZQ, 'edgecolor', 'none');

xlabel('x'); ylabel('y'); zlabel('z')

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Sangani Prithvi 2021-9-2

Thank you very much.

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Answer 2

KSSV 2021-9-2

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1445199-problem-with-interpolation-function-involving-2-variables#answer_779344

在 MATLAB Online 中打开

T = readtable('xyz.xlsx') ; 
x = T.X ; y = T.Y ; z = T.Z; 
Xq = -60:60 ;
Yq = -160:160.  ; 
[Xq,Yq] = meshgrid(Xq,Yq) ; 
Zq = griddata(x,y,z,Xq,Yq) ; 