Concatenate cell with numeric array in tables

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I have a ridiculously simple problem that I cannot solve. I have two tables and I want to concatenate them, but one contains a column with a cell array and one with a numeric array.
a = table([1; 2; 3]);
b = table({[1 2]; [3 4]})
c = [a; b];
This immediately produces an error because I am trying to concatenate a cell with a non-cell type. But if I just try to concatenate these variables outside a table, it works fine, recognizing that the result should be a cell array. There seems to be no way of telling matlab that I want it to convert a's variable to a cell array.
The actual problem is somewhat more complex - it's easy enough to solve this in the current case by just removing the variables from the table and concatenating them, then making a new table. But in the actual use case the tables have up to 50 variables, and it's unknown at runtime which of them are causing the problem.
Suggestions?

Accepted Answer

Robert U
Robert U on 30 Oct 2019
Hi Marcus Watson,
an straight-forward solution would be checking the variable types stored in the table. In case they don't match change the numerical one to cell array.
a = table([1; 2; 3]);
b = table({[1 2]; [3 4]})
if ~cellfun(@isempty,{a{:,vartype('numeric')}}) && cellfun(@isempty,{b{:,vartype('numeric')}})
a = table({a{:,vartype('numeric')}});
elseif cellfun(@isempty,{a{:,vartype('numeric')}}) && ~cellfun(@isempty,{b{:,vartype('numeric')}})
b = table({b{:,vartype('numeric')}});
end
c = [a; b];
In case there are anyway no numerical values to concatenate you can change all tables that are containing numerical values to cells.
Kind regards,
Robert
  5 Comments
Marcus Watson
Marcus Watson on 1 Nov 2019
Apologies my previous comment's code did not actually do the same as yours. Yours is the only one that I've seen work.

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