How to interpolate 2 dimensions of a 4D array ?

Question

bhakti 2023-12-5

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https://ww2.mathworks.cn/matlabcentral/answers/2056589-how-to-interpolate-2-dimensions-of-a-4d-array

评论： bhakti 2023-12-8

I have a 4D array which represents velocity(ocean currents) in a region, and I have to interpolate it to a different size.

Some insights on data;

1) Variables of 4 D array are (Longitude, latitude, depth, time).

2) Size of the array is [176,239,5,248]. I have to change/interpolate the size of array to [112,152,5,248]. Can someone please help in making the above said change(s)?

This is link to data file.

https://drive.google.com/file/d/1Jcp6F1-Bv85FUMyITiGa0AJncKnLsUMF/view?usp=drive_link

Thanks in advance!

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KALYAN ACHARJYA 2023-12-5

Please provide the array sizes [x,y,z,t]?

bhakti 2023-12-5

编辑：bhakti 2023-12-5

Hello Kalyan,

Thanks for your response.

Size of the array is [176,239,5,248] and it has to be changed/interpolated to [112,152,5,248].

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Answer 1

Torsten 2023-12-6

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https://ww2.mathworks.cn/matlabcentral/answers/2056589-how-to-interpolate-2-dimensions-of-a-4d-array#answer_1366804

移动：Torsten 2023-12-6

在 MATLAB Online 中打开

% Generate artificial data in longitude and latitude (176 points resp. 239
% points)
longdata = linspace(0,2,176);
latdata = linspace(0,5,239);
veldata = rand(numel(longdata),numel(latdata),5,248);
% Prescribe new grid in longitude and latitude direction (112 points resp.
% 152 points)
longdata_new = linspace(0,2,112);
latdata_new = linspace(0,5,152);
% Build new grid
[longq,latq] = meshgrid(longdata_new,latdata_new);
% Compute new velocity data
veldata_new = zeros(numel(longdata_new),numel(latdata_new),5,248);
for iz = 1:5
    for it = 1:248
        veldata_cut = veldata(:,:,iz,it);
        veldata_new(:,:,iz,it) = interp2(longdata,latdata,veldata_cut.',longq,latq).';
    end
end

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bhakti 2023-12-8

Thank you!

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Answer 2

Sulaymon Eshkabilov 2023-12-5

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https://ww2.mathworks.cn/matlabcentral/answers/2056589-how-to-interpolate-2-dimensions-of-a-4d-array#answer_1366199

Your data size is [176 238 5 248] and not [176,239,40,248].

In this case, interpolate your multi-D data, griddatan() to be used: DOC

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Torsten 2023-12-6

And you want to compute velocity on a new grid for Longitude and Latitude with depth and time unchanged ?

bhakti 2023-12-6

Hello Torsten,

Thanks for your response.

Yes, that's what I am looking for.

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Answer 3

Matt J 2023-12-5

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2056589-how-to-interpolate-2-dimensions-of-a-4d-array#answer_1366279

在 MATLAB Online 中打开

You can use imresizen, to be downloaded from

https://www.mathworks.com/matlabcentral/fileexchange/64516-imresizen-resize-an-n-dimensional-array?s_tid=srchtitle

A= rand([176,239,5,248]);
B=imresizen(A, [112,152,5,248]./[176,239,5,248]);
whos A B
  Name        Size                       Bytes  Class     Attributes

  A         176x239x5x248            417274880  double              
  B         112x152x5x248            168878080  double              