Extract same row and columns of matrix

name = ['A1', 'A2', 'A3', 'A4', 'A5', 'A6';...
    'B1', 'B2', 'B3', 'B4', 'B5', 'B6';...
    'C1', 'C2', 'C3', 'C4', 'C5', 'C6';...
    'D1', 'D2', 'D3', 'D4', 'D5', 'D6';...
    'E1', 'E2', 'E3', 'E4', 'E5', 'E6';...
    'F1', 'F2', 'F3', 'F4', 'F5', 'F6'];
col = 1:6;
row = ['A','B','C','D','E','F'];

all_pcs = zeros(6,6,2);         
all_locs = [];


for i = 1:size(xycenters,1)
    
    
    xc = xycenters(i,1);
    yc = xycenters(i,2);
    xloc = 0;
    
    for linex = 1:size(xprime,2)
        if xc > mean(xprime(:,linex)) && xc < mean(xprime(:,linex+1))
            xloc = linex;
        end
    end
    
    yloc = 0;
    for liney = 1:size(yprime,2)
        if (yc > mean(yprime(:,liney))) && (yc < mean(yprime(:,liney+1)))            
            yloc = liney;
        end
    end
    %xloc, yloc
    all_pcs(yloc, xloc, :) = [xc, yc];
    all_locs = [all_locs;(strcat(row(yloc), num2str(col(xloc))))];
    
    
end


disp('There is RedPawn:')
disp(sortrows(all_locs))

Result :

Red pawn :

A2

C4

C4

E4

I just want to extract the twins C4 and put it in other variable. Like this

Result i want :

Red Pawns:

A2

E4

Queen :

C4

Answer 1

[Arif Hoq]

you can find your answer here

https://www.mathworks.com/matlabcentral/answers/266736-how-can-i-find-same-values-in-an-array

Red_pawn={'A2';'C4';'C4';'E4'};
[C ia ic]=unique(Red_pawn,'stable');
c = bsxfun(@eq,ic,ic.');
x = any(tril(c,-1)|triu(c,1),1);
A=x(:);
queen=unique(Red_pawn(A==1))

queen = 1×1 cell array
    {'C4'}

Red_pawn=unique(Red_pawn(A==0))

Red_pawn = 2×1 cell array
    {'A2'}
    {'E4'}

[Fh rtr]

Thx Arif Hoq i found the solution