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Convert cell array to matrix with two columns and sort rows by first column value

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Nik Rocky
Nik Rocky on 10 Feb 2021
Commented: Nik Rocky on 10 Feb 2021
Hello,
I have a large Cell array with multiple cells. Every these cells has n-rows and two columns.
I want to convert this cell-array to one large matrix with j x 2 double matrix (j is sum value of all rows of all cells)
Cell_x =
1×8 cell array
Columns 1 through 4
{13×2 double} {10×2 double} {9×2 double} {11×2 double}
Columns 5 through 8
{9×2 double} {12×2 double} {6×2 double} {7×2 double}
Matrix_x =
77 x 2 double
after it, I want to sort the rows by values of the first column:
Test_unsorted =
4 45
8 78
9 77
1 68
Test_sorted =
1 68
4 45
8 78
9 77
Thank you for your help!

Accepted Answer

Stephen Cobeldick
Stephen Cobeldick on 10 Feb 2021
Edited: Stephen Cobeldick on 10 Feb 2021
More robust and more efficient than using cell2mat:
M = vertcat(Cell_x{:});
M = sortrows(M,1)

More Answers (1)

the cyclist
the cyclist on 10 Feb 2021
Edited: the cyclist on 10 Feb 2021
I think this does what you want:
% Set RNG seed, for repeatability
rng default
% Make up some data
Cell_x = {rand(13,2),rand(7,2)};
% Convert cell to matrix, and sort rows by first column
sortrows(cell2mat(Cell_x'),1)
ans = 20×2
0.0318 0.9502 0.0975 0.7922 0.1270 0.1419 0.1576 0.9340 0.1712 0.6948 0.2769 0.0344 0.2785 0.9595 0.3922 0.0971 0.5469 0.6557 0.6324 0.9157

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