# Cell array to meet conditions and cell indexing

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Matlab User on 22 Feb 2016
Commented: Guillaume on 23 Feb 2016
I apologise in advance for incase this is unclear.
I have an array, with X Y columns and another column that identifies the other X and Ys that have met a previous condition. For example A=[16x1 double 16x1 double 8; 12x1 double 12x1 double []; 15x1 double 15x1 double [13,15]..... up to 19 rows]. If the condition was not met there is no match and so the third column reads [], as given for A(2,:). If two sets of x and y coordinates have been matched, then these can be found in rows 13 and 15 for example of column 1, for A(3,:).
I want to therefore have an output of the original X and Y sets, the matching rows (I already have) and the matching X Y coordinates. I had had numerous errors since there are empty cells, which I do not want to delete. Also, the number of matches changes each time, so concatenating brings errors.
Thankyou.
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Matlab User on 22 Feb 2016
Thankyou, so here I have my X and Y coordinates in the first two columns. In the third i have the row numbers that match the condition i imposed. For example, for the first row, I would like to join the X Y coordinates for this row with that of the 8th row, as they have met the match. Similarly, for the third row the X Y coordinates have made a match with rows 13 and 15 so, I would like to join the X and Y for the 3rd, 13th and 15th row together, etc. Thankyou.

Guillaume on 22 Feb 2016
I'm not really clear on the format of the output you want, but the following should give you an idea what to do:
C = {[1:10]', [21:30]', 8; [41:45]', [51:55]', [2 4]; [60:70]', [80:90]', []} %demo data
C(:, 4) = cellfun(@(x, y, row) [x(row), y(row)], C(:, 1), C(:, 2), C(:, 3), 'UniformOutput', false)
celldisp(C(:, 4))
Guillaume on 23 Feb 2016
The loop solution should have read:
rows = X_Y_Match{rowidx, 3};