How to slice an array across multiple dimensions with two limit arrays?

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Brian Kardon
Brian Kardon on 22 Apr 2022
Edited: Bruno Luong on 22 Apr 2022
I'm interested in taking an arbitrary N-dimensional array, and two 1xN vectors, and using the two vectors as start/stop indices to slice the array, but I'm not sure how. Here's what I mean:
Let X be an N-dimensional array.
Let A and B be 1xN vectors like so:
A=[a1, a2, ..., aN]
B=[b1, b2, ..., bN]
How do I slice X such that I get this:
Y = X(a1:b1, a2:b2, ..., aN:bN)
I tried X(A:B), but that doesn't work - not even sure what that operation is doing, but it isn't doing what I want. I tried to think of some way to do it with logical indexing, but nothing simple came to mind. I could slice the array one dimension at a time in a loop, but it seems like there must be a one-liner. Thanks!

Accepted Answer

Bruno Luong
Bruno Luong on 22 Apr 2022
Edited: Bruno Luong on 22 Apr 2022
This should work
X=rand(6,6,6);
A=[1 2 3]; B=[6 5 4];
cidx = arrayfun(@(i1,i2) i1:i2, A, B, 'unif', 0);
Y = X(cidx{:})
Y =
Y(:,:,1) = 0.7739 0.3475 0.5936 0.5165 0.5514 0.0120 0.8295 0.7020 0.7219 0.0188 0.0139 0.2095 0.6081 0.2888 0.2122 0.9462 0.7840 0.4617 0.7677 0.1717 0.3399 0.1233 0.8264 0.1021 Y(:,:,2) = 0.8648 0.4441 0.7968 0.1729 0.2677 0.8310 0.6914 0.3000 0.7044 0.0935 0.5411 0.2597 0.1844 0.8915 0.9166 0.0287 0.8937 0.8579 0.5319 0.6198 0.1937 0.8000 0.0968 0.2708

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