remove all strings from nested cell array

Question

Davindra Usov 2022-6-22

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1746060-remove-all-strings-from-nested-cell-array

评论： Davindra Usov 2022-7-7

Hi,

I'm trying to remove all string/chars from a 4x10 cell array where each cell in the array contains a 40x1 column vector (so as you can see, it's nested). Most commands I usually use such as cell2mat don't work on this because the cell array is nested.

Or, if preferred, is there a way to read in all the elements of a certain column in one of the cells in a cell array apart from the elements containing strings? e.g:

col=rand(4,10) %matrix containing column indices
for i=1:4
    for j=1:10
        new_cell_arrray{i,j}=g{i,1}(:,col(i,j)); %g is another (existing) 4x1 cell array and new_cell_array is 4x10.
    end
end

Thank you

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Walter Roberson 2022-6-22

If you "remove" an entry from a 2D array, the result cannot be a 2D array any more.

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Answer 1

Walter Roberson 2022-6-22

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1746060-remove-all-strings-from-nested-cell-array#answer_991455

在 MATLAB Online 中打开

C = num2cell(randi(9,4,10));
C(randperm(numel(C), 4)) = {"string"};
C(randperm(numel(C), 4)) = {'chars'};
C
C = 4×10 cell array
    {[5]}    {[       8]}    {[5]}    {[6]}    {[1]}    {[       8]}    {'chars'}    {'chars'   }    {["string"]}    {'chars'}
    {[3]}    {["string"]}    {[4]}    {[1]}    {[2]}    {["string"]}    {[    1]}    {[       9]}    {[       5]}    {[    8]}
    {[8]}    {[       5]}    {[4]}    {[8]}    {[9]}    {[       2]}    {[    1]}    {[       5]}    {[       6]}    {[    7]}
    {[3]}    {[       3]}    {[5]}    {[1]}    {[5]}    {[       2]}    {'chars'}    {["string"]}    {[       9]}    {[    8]}
for K = 1 : size(C,2)
    mask = ~cellfun(@(c)ischar(c)||isstring(c), C(:,K));
    subset{K} = C(mask, K);
end
subset
subset = 1×10 cell array
    {4×1 cell}    {3×1 cell}    {4×1 cell}    {4×1 cell}    {4×1 cell}    {3×1 cell}    {2×1 cell}    {2×1 cell}    {3×1 cell}    {3×1 cell}
subset{1}, subset{2}
ans = 4×1 cell array
    {[5]}
    {[3]}
    {[8]}
    {[3]}
ans = 3×1 cell array
    {[8]}
    {[5]}
    {[3]}

5 个评论
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Walter Roberson 2022-6-24

在 MATLAB Online 中打开

"In each cell, I have 4 strings and 36 numbers."

Okay, I will generate 4 strings and 36 numbers per cell.

for J = 1 : 4
    for K = 1 : 10
        thiscell = num2cell(randi(9, 40, 1));
        rp = randperm(40,4);
        thiscell(rp) = {"string"};
        C{J,K} = thiscell;
    end
end
whos C
  Name      Size             Bytes  Class    Attributes

  C         4x10            206080  cell               
C{1}
ans = 40×1 cell array
    {[       4]}
    {[       1]}
    {[       4]}
    {[       4]}
    {[       1]}
    {[       3]}
    {[       1]}
    {[       6]}
    {[       4]}
    {["string"]}
    {[       4]}
    {[       7]}
    {["string"]}
    {[       1]}
    {[       3]}
    {[       5]}
subset = cell(size(C));
for J = 1 : numel(C)
    mask = ~cellfun(@(c)ischar(c)||isstring(c), C{J});
    subset{J} = C{J}(mask);
end
whos subset
  Name        Size             Bytes  Class    Attributes

  subset      4x10            165440  cell               
subset{1}
ans = 36×1 cell array
    {[4]}
    {[1]}
    {[4]}
    {[4]}
    {[1]}
    {[3]}
    {[1]}
    {[6]}
    {[4]}
    {[4]}
    {[7]}
    {[1]}
    {[3]}
    {[5]}
    {[5]}
    {[5]}