CODEWITHSUNDEEP
matlabmultidimensional-arraypermutationvectorization
huynh khactuan
huynh khactuan

Reputation: 35

Replicate and permute in 4D

Let X1, X2, X3, X4 be row vectors of size [1xN1], [1xN2], [1xN3] and [1xN4] respectively. I would like to replicate and rotate these row vectors to obtain 4 corresponding 4D arrays A1, A2, A3 and A4 with size [N1xN2xN3xN4]. X1 corresponds the 1st dimension of A1, X2 corresponds the 2nd dimension of A2, X3 corresponds the 3rd dimension of A3, and X4 corresponds the 4th dimension of A4. For example, I can obtain A1 and A2 as follows

A1=repmat(X1',[1 N2 N3 N4]);
A2=repmat(X2,[N1 1 N3 N4]);

A3 can be obtained with the following "amateur" code

A3Temp=repmat(X3,[N2 1 N1]); % [N2xN3xN1] array
A3TempRot=rot90_3D_2t(A3Temp,2,3,1,1); % Rotate 2 times to obtain [N1xN2xN3] array
A3=repmat(A3TempRot,[1 1 1 N3]);

For A4, I do not know how to do. After that, I would like to rotate these arrays to obtain [N4xN2xN3xN1] arrays. Do you have any idea about this? Thank you in advance for your help.

Tuan

Upvotes: 0

Views: 275

Answers (1)

Shai
Shai

Reputation: 114786

have you looked at ndgrid?

[A2 A1 A3 A4] = ndgrid(x2, x1, x3, x4);

Notice how A1 and A2 are ordered according to x2 and x1 due to the slight difference in functionality between ndgrid and meshgrid.

Upvotes: 1

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