interpolate 3 dimensional arrays (in time and space)

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wave_buoys
wave_buoys 2018-8-28
评论： wave_buoys 2018-8-29
Hi all,
I have 3D matrix 180x90x120 which is equal to lonxlatxtime. In space, the data has 1 degree resolution (e.g. longitude ranges from 1 to 180), while the time interval is 3 hours (e.g. 3h, 6h, 9h.....).
Now I want to interpolate data to get a finer resolution of 0.5 degree and with 1-hour interval, so the new matrix would be 360x180x360.
Could you please help?
Thanks
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Matt J
Matt J 2018-8-28
编辑：Matt J 2018-8-28
No, do not use griddata for this. KL's suggestion of griddedInterpolant was appropriate. See also my second answer.
Matt J
Matt J 2018-8-28
编辑：Matt J 2018-8-28
Now I want to interpolate data to get a finer resolution of 0.5 degree and with 1-hour interval, so the new matrix would be 360x180x360.
Those will not be the new dimensions. If you sample from 1 to 180 at intervals of 0.5, you will obtain 359 points, not 360. Similarly for the other dimensions.

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采纳的回答

Matt J
Matt J 2018-8-28
编辑：Matt J 2018-8-28
F=griddedInterpolant(yourData);
qlon=(1:.5:180);
qlat=(1:.5:90);
qtime=(1:1/3:120);
newData=F({qlon,qlat,qtime});
  2 个评论
wave_buoys
wave_buoys 2018-8-29
Dear Matt J,
Sorry. It works but the outcomes are not as I expected. Particularly the new results look weird. Perhaps I also misunderstood about the input matrix format. To be corrected, the 3D matrices I mentioned, for instance, 180x90x120 contains 120 2D arrays size (180x90) for monthly wind speeds in Longitude and Latitude direction. These 120 matrices correspond to a 1D time matrix (which is separated): 0h 6h 12h 18h.....720h..
So when I use:
v = winddata % (size: 180x90x120)
F= griddedInterpolant(v)
qlon=(1:.5:180)
qlat=(1:.5:90);
qtime=(1:1/3:120);
newwinddata=F({qlon,qlat,qtime});
it does not work properly because time does not present in griddedInterpolant(v).
May you help more? Thanks

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更多回答（1 个）

Matt J
Matt J 2018-8-28
编辑：Matt J 2018-8-28
You could download IMRESIZEN, and then do things like,
>> A=rand(180,90,120); B=imresizen(A,[2,2,3]); whos B
Name Size Kilobytes Class Attributes
B 360x180x360 182250 double
  2 个评论
wave_buoys
wave_buoys 2018-8-28
编辑：Matt J 2018-8-28
Thanks Matt, but it does not for my situation because Imresizen just scales up the data.
Has anyone done something similar to this? May you help?
Thanks
Matt J
Matt J 2018-8-28
How is that different from what you are trying to do?

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