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How can i reorder NxM matrix into a 1D array

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I am looking to take a sample matrix below. The matrix will be large and looking for fast and non looping solution. Thank you.
a=[1 2 3;4 5 6;7 8 9];
reshape it into:
b=[7 8 9 4 5 6 1 2 3];

  1 Comment

Matthew
Matthew on 12 Jun 2018
No the matrix is not always 3 rows. It will likely be much more in both rows and columns.

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Accepted Answer

Star Strider
Star Strider on 12 Jun 2018
Using the reshape (link) function:
b = reshape(a([3 2 1],:)', 1, [])
b =
7 8 9 4 5 6 1 2 3

  1 Comment

Stephen Cobeldick
Stephen Cobeldick on 12 Jun 2018
Or generalized for any number of rows:
reshape(a(end:-1:1,:).', 1, [])

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More Answers (1)

Alfonso
Alfonso on 12 Jun 2018
Without looping you can do:
b = [a(end,:), a(end-1,:), a(end-2,:)]; % 1D array
b =
7 8 9 4 5 6 1 2 3
You can repeat the iterations as many rows you have: [a(end-1,:), ... ,a(end-50,:)]

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