How to break a large table into a set of smaller tables?

https://www.mathworks.com/matlabcentral/answers/229847-how-to-break-a-large-table-into-a-set-of-smaller-tables

This question is asked before and my problem is that the one of the columns are string not numbers and I recieve this error "Error using ==

Comparison between double and string is not supported." when using this code taken from the answers to the above question:

col24 = T{:,[27 28]};
u24 = unique(col24, 'rows');
numentry = size(u24,1);
TableCell = cell(numentry,1);
for K = 1 : numentry
  insubset = T{:,27} == u24(K,1) && T{:,28} == u24(K,2);
  TableCell{K} = BigTable(insubset,:);
end

Alos is it possible to use the name of columns instead of numnber so instead of 27 and 28 which are the column number in col24 = T{:,[27 28]}; use the name of those columns?

[Walter Roberson]

col24 = T{:, {'x', 'y'}};

would be an example of extracting by variable names x and y.

Would I be correct is saying that one of the variables is string datatype and the other variable is numeric ?

[Mohammad Sami]

For string datatype, using functions such as contains, startsWith, endsWith for comparison.

Answer 1

[Walter Roberson]

col24 = T(:,[27 28]);    %notice () not {} . Output is table
u24 = unique(col24, 'rows');  %output is table
numentry = size(u24,1);
TableCell = cell(numentry,1);
for K = 1 : numentry
  insubset = strcmp(T{:,27},u24{K,1}) & T{:,28} == u24{K,2};  %notice {} not ()
  TableCell{K} = T(insubset,:);
end

Note: this code should work even if column 27 is cell array of character vector instead of string data type. If you are sure you will have string() datatype then

  insubset = T{:,27} == u24{K,1} & T{:,28} == u24{K,2};

will also work.

[Zeynab Mousavikhamene]

It gave me empty cell arrays. Do you know why?

I guess the problem is from

insubset = strcmp(T{:,27},u24{K,1}) & T{:,28} == u24{K,2};  

as it gives all zero in the whole loop

[Zeynab Mousavikhamene]

Substituting with this line worked:

  insubset = T{:,27} == u24{K,1} & T{:,28} == u24{K,2};

I dont think this line is correct:

    insubset = strcmp(T{:,27},u24{K,1}) & T{:,28} == u24{K,2};  %notice {} not ()

GREAT JOB Walter. You are awesome!

[Zeynab Mousavikhamene]

By the way waht is TableCell? Is it cell array?

How can I convert that to TableCell to individual tables?

[Walter Roberson]

TableCell is a cell array that contains tables. You can use TableCell{1}, TableCell{2} and so on to extract the individual tables. You would not assign them to individual variables because you do not know how many there are. http://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Answer 2

[Zeynab Mousavikhamene]

@Walter Roberson

Yes onn of the columns of table are string (column 27) the other is numeric.