Append rows of string in a table

Imagine the following table:

id = {1; 1; 2; 2; 3};
someStr = {"how are"; "you"; "I am"; "fine"; "some text" }; 
T = table(id, someStr); 

What I am trying to do is to append lines with same id. In the end the table must look like this:

idNew = {1; 2; 3};
someStrNew = {"how are you"; "I am fine"; "some text"};
Tnew = table(idNew, someStrNew); 

Is there a way to do this in matlab?

Answer 1

[Star Strider]

I can get it to work with character arrays, however not with string objects. I cannot get the char (or similar functions, such as convertStringsToChars) conversion from string objects to character arrays to work inside these functions.

Try this:

id = {1; 1; 2; 2; 3};
% someStr = {"how are"; "you"; "I am"; "fine"; "some text" };             % Commented Out
someStr = {'how are'; 'you'; 'I am'; 'fine'; 'some text' }; 

Out = accumarray([id{:}]', (1:numel(id))', [], @(x){someStr(x)'});
Out = cellfun(@(x)strjoin(x), Out, 'Uni',0)

producing:

Out =

  3×1 cell array

    {'how are you'}
    {'I am fine'  }
    {'some text'  }

You would likely have to extract everything from the table first. Using table objects have their advantages, however here they simply introduce an additional level of complexity.

[Sergiu Panainte]

Thank you so much, it worked!

Yeah, extracting from table helped me...although at the end I need a table, for temporary results it was quite helpful

[Star Strider]

As always, my pleasure!

It is straightforward to create the results as a table after doing the concatenations. Doing them in the table makes it considerably more difficult.

.