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Unique elements in cell array

version 1.0.0.0 (1.4 KB) by Patrick Mineault
unique for numeric cell arrays. If c = {[0],[1,2],[0],[8],[1,2]} returns {[0],[1,2],[8]}

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Updated 08 Jun 2011

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function [Au, idx, idx2] = uniquecell(A)

Same as built-in unique, but works for cell arrays where each element is a numeric array.

For A a cell array of matrices (or vectors), returns Au, which contains the unique matrices in A, idx, which contains the indices of the last appearance of each such unique matrix, and idx2, which contains th indices such that Au(idx2) == A

Example usage:

A = {[1,2,3],[0],[2,3,4],[2,3,1],[1,2,3],[0]};
[Au,idx,idx2] = uniquecell(A);

Results in:

idx = [6,5,4,3]
Au = {[0],[1,2,3],[2,3,1],[2,3,4]}
idx2 = [2,1,4,3,2,1]

Algorithm: uses cellfun to translate numeric matrices into strings then calls unique on cell array of strings and reconstructs the initial matrices.

Cite As

Patrick Mineault (2021). Unique elements in cell array (https://www.mathworks.com/matlabcentral/fileexchange/31718-unique-elements-in-cell-array), MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2008b
Compatible with any release
Platform Compatibility
Windows macOS Linux
Acknowledgements

Inspired: uniqueCellGeneralized(A), uniqueCells

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