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How to write this line of code to create a Matlab table?

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Leon 2020-12-5

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评论： Leon 2020-12-5

采纳的回答： Walter Roberson

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I have unknown number of column variables in cell array:

Var{1} = [ 1; 2; 3; 4; 7];
Var{2} = [33; 10; 46; 7; 2];
...

If I knew how many variables I have, I would be able to manually form my table by:

T1 = table(Var{1}, Var{2}, ...);

The problem is that I do not know how many variables each time my program will generate. In this case, how could I write the code to create the table?

I tried the below, but it does not work:

T1 = table(Var);

Many thanks.

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Walter Roberson 2020-12-5

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cell2table and probably provide VariableNames parameter

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Many thanks for pointing me towards that direction.

Below is my code. Unfortunately, it still does not work

TT = cell2table(Var);
File_W = 'test.xlsx';
writetable_units(TT, File_W);

Error using writetable_units (line 11)
The data block starting at cell 'A3' exceeds the sheet
boundaries by 0 row(s) and 1874492 column(s).
Error in A01_NC (line 68)
writetable_units(TT, File_W);

Here is what my Var look like:

Var =
  1×69 cell array
  Columns 1 through 3
    {27404×1 double}    {27404×12 char}    {27404×12 char}
  Columns 4 through 6
    {27404×1 char}    {27404×1 char}    {27404×9 char}

Walter Roberson 2020-12-5

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I am not able to find any function named writetable_units. The error message suggests that whatever it is, it is not written in MATLAB m code so it might be difficult to find source code for.

Walter Roberson 2020-12-5

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The error message refers to 1874492 columns, which is far beyond the limit for xlsx files. However it is not obvious to me how it could have gotten that many columns out of your data, which is why I would need to look at the source code.

Walter Roberson 2020-12-5

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Though I do notice that you only happen to show the first 6 out of 69 cells. Is it possible that some of the cells contain numeric values with more than one column? For example 27204 x 20000 double would need 20000 excel columns which would be too much for xlsx format.

Leon 2020-12-5

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Thanks, Walter!

Please ignore the readtable_units function. It is a slightly modified version of the readtable. It is essentially the same as the readtable function. This error is unrelated to that function for sure.

My data has 69 columns, each column has 27404 rows. That's it. The 1874492 columns probably is a proof that the below command is not working as we hope it should.

TT = cell2table(Var);

Walter Roberson 2020-12-5

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What does size(TT) show? Also experiment with cell2table(Var(:))

Leon 2020-12-5

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Many thanks!

Size(TT) shows: 1 x 69.

I also tested TT=cell2table(Var(:)) and the size(TT) shows: 69 x 1.

Walter Roberson 2020-12-5

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vartypes = cellfun(@class, Var, 'uniform', 0);
nonchar = find(~ismember(vartypes, {'string', 'char'}));
varsizes = cellfun(@size, Var, 'uniform', 0);
vardims = cellfun(@ndims, Var);
oddsized = find(vardims ~= 2);
if ~isempty(oddsized)
    fprintf('Some variables are multi-dimensional! Index: \n');
    disp(oddsized)
    fprintf('sizes:\n');
    celldisp(vardims(oddsized))
end
nonchar = setdiff(nonchar, oddsized);    %don't complain twice
nonchar_sizes = vertcat(varsizes{nonchar});
multicol = find(nonchar_sizes(:,2) > 1);
if ~isempty(multicol)
    fprintf('Some non-char variables have multiple columns! Index: \n');
    disp(nonchar(multicol));
    fprintf('sizes:\n');
    nonchar_sizes(multicol, :);
end
if isempty(oddsized) && isempty(multicol)
    fprintf('All non-char variables are single column, as desired\n');
end