How to sort a cell array with respect to another cell array?

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Liam on 27 Jun 2023
Commented: Liam on 27 Jun 2023
Hello:
If I have cell array A:
cellA = {'A', 'B', 'C', 'D'; 1, 2, 3, 4; 5, 6, 7, 8; 9, 1, 2, 3}
cellA = 4×4 cell array
{'A'} {'B'} {'C'} {'D'} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]} {[1]} {[2]} {[3]}
and cell array B:
cellB = {'C', 'A', 'D'; 1, 2, 3; 4, 5, 6; 7, 8, 9}
cellB = 4×3 cell array
{'C'} {'A'} {'D'} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}
Is there a way to sort cellB with respect to cellA (specifically the first row, but with the capability to look to other rows to tiebreak)? Such that the final cellB array looks something like this, including the null spaces:
cellBFinal = {'A' '' 'C' 'D'; 2 [] 1 3; 5 [] 4 6; 8 [] 7 9}
cellBFinal = 4×4 cell array
{'A'} {0×0 char } {'C'} {'D'} {[2]} {0×0 double} {[1]} {[3]} {[5]} {0×0 double} {[4]} {[6]} {[8]} {0×0 double} {[7]} {[9]}
Thank you!

Dyuman Joshi on 27 Jun 2023
Here's one approach -
%Note that this approaches requires the 1st row of cellA to be sorted
cellA = {'A', 'B', 'C', 'D'; 1, 2, 3, 4; 5, 6, 7, 8; 9, 1, 2, 3};
cellB = {'C', 'A', 'D'; 1, 2, 3; 4, 5, 6; 7, 8, 9};
%positions of elements of row 1 from cellB which are common to elements of row 1 from cellA
[~,y]=ismember(cellA(1,:),cellB(1,:))
y = 1×4
2 0 1 3
z = any(y==0);
if z
%Concatenate empty spaces according to the class of elements with cellB
%only there is a missing common element (in this case 'B')
cellB = [cellfun(@(x) x([]), cellB(:,1), 'uni', 0) cellB];
end
%Final output
cellC = cellB(:,y+z)
cellC = 4×4 cell array
{'A'} {0×0 char } {'C'} {'D'} {[2]} {0×0 double} {[1]} {[3]} {[5]} {0×0 double} {[4]} {[6]} {[8]} {0×0 double} {[7]} {[9]}
Jon on 27 Jun 2023
I see, thanks for the clarification.
Liam on 27 Jun 2023
Thank you! This method works great.

Jon on 27 Jun 2023
cellA = {'A', 'B', 'C', 'D'; 1, 2, 3, 4; 5, 6, 7, 8; 9, 1, 2, 3}
cellA = 4×4 cell array
{'A'} {'B'} {'C'} {'D'} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]} {[1]} {[2]} {[3]}
cellB = {'C', 'A', 'D'; 1, 2, 3; 4, 5, 6; 7, 8, 9}
cellB = 4×3 cell array
{'C'} {'A'} {'D'} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}
[lia,lib] = ismember(cellA(1,:),cellB(1,:))
lia = 1×4 logical array
1 0 1 1
lib = 1×4
2 0 1 3
cellBFinal = cell(size(cellA,2),size(cellB,1))
cellBFinal = 4×4 cell array
{0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double}
cellBFinal(:,lia) = cellB(:,lib(lia))
cellBFinal = 4×4 cell array
{'A'} {0×0 double} {'C'} {'D'} {[2]} {0×0 double} {[1]} {[3]} {[5]} {0×0 double} {[4]} {[6]} {[8]} {0×0 double} {[7]} {[9]}
Jon on 27 Jun 2023
@Liam if it is important to you to have all the elements of the first row as char, then @Dyuman Joshi's somewhat more elaborate construction of the empty cell array will be needed. Otherwise can just initialize with all elements as empty doubles.
Liam on 27 Jun 2023
Yes, the first element does need everything to be characters (I suppose it could be converted quite easily in a later step so your method also works great).

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