Searching in cell arrays.

hi i have 2 cell arrays:

array1={6x6 double;6x6 double} & its elements are:

array1{1,1}=[0,0,0,0,0,0;0,0,0,0,0,0;0,2,0,0,0,0;1,2,3,4,0,0;0,0,0,0,0,0;0,0,0,0,0,0]
array1{2,1}=[0,0,3,4,0,0;1,0,3,4,0,0;0,2,0,0,0,0;1,2,3,4,0,0;0,0,0,0,0,0;0,0,0,0,0,0]

second cell array is:

array2={{[3;4]};[1;2;3;4]}

i want to search all elements of array2 (one by one) in corresponding cell of array1 and if found replace it with its row index.

Thanks in advance.

[Rik]

I don't understand what exactly it is that you want to do. One part of that is that code is not readable. Use the {}Code button.

What do you expect the outcome to be?

[Stephen23]

Duplicate:

https://www.mathworks.com/matlabcentral/answers/333551-finding-row-indexes-in-array

https://www.mathworks.com/matlabcentral/answers/333553-compare-elements-of-cell-and-2d-array

Answer 1

[Guillaume]

I'm not entirely sure of the output you want. Maybe:

function rows = findrow(matrix, value)
   %find the rows of matrix where value is found
   [rows, ~] = find(matrix == value);
   rows = unique(rows);
end

Used with your cell arrays:

array1 = {[0,0,0,0,0,0;0,0,0,0,0,0;0,2,0,0,0,0;1,2,3,4,0,0;0,0,0,0,0,0;0,0,0,0,0,0];
          [0,0,3,4,0,0;1,0,3,4,0,0;0,2,0,0,0,0;1,2,3,4,0,0;0,0,0,0,0,0;0,0,0,0,0,0]};
array2 = {[3;4]; [1;2;3;4]};  %I assume the cell array within cell array was a typo

out = cellfun(@(m, v) arrayfun(@(v) findrow(m, v), v, 'UniformOutput', false), ...
              array1, ...
              array2, ...
              'UniformOutput', false)

[lucksBi]

Thanks alot for your answer..yes sorry that was a typo. It gives following error

Error using arrayfun All of the input arguments must be of the same size and shape. Previous inputs had size 13 in dimension 2. Input #3 has size 1.

I am clueless about this message.

[Guillaume]

Right, I'd made two typos on the cellfun line. Fixed now.

[lucksBi]

Thank you so much for this very optimal piece of code.

Answer 2

[Andrei Bobrov]

another variant

m - file:

function out = findrows(a,b)
  [~,ii] = ismember(a,b);
  [i1,~] = find(ii);
  out = accumarray(ii(ii > 0),i1,[],@(x){unique(x)});
end

using:

out = cellfun(@(x,y)findrows(x,y),array1,array2,'un',0);

[lucksBi]

Good one.. thanks alot.