Table header - possible to use special characters?

I have constructed a table with data from a struct and now wish to add custom headers to the columns before exporting the table. I found the following command:

T.Properties.VariableNames{'OldHeader'} = 'NewHeader';

This command however does not allow me to use spaces or special characters for my headers. My table contains the output from processed lab data and I wish to have headers like this:

"Vol. [mL]" and "Conc. [wt%]"

Is this in any way possible?

Answer 1

[Andrew Reibold]

I don't know if it actually works: Try using sprintf to print what text you want

[Morten Jensen]

one of the columns would be

sprintf('Vol. [mL]')

which I can't seem to get to work as a header.

Taking mathworks own example from struct2table documentation :

S.Name = {'CLARK';'BROWN';'MARTIN'};
S.Gender = {'M';'F';'M'};
S.SystolicBP = [124;122;130];
S.DiastolicBP = [93;80;92];
T = struct2table(S)
T.Properties.VariableNames{'Gender'} = 'Sex';

The above works, but restricts me to normal characters and no spaces. My question is how to change "Gender" to "Vol. [mL]" - if even possible.

[Andrew Reibold]

So I had a spare second and just tried to establish "Vol mL" as a variable name not even include the special characters, and it says it was not an allowable variable name (Just for the space!)

I then tried to establish just "Vol[mL]" and was denied as well (Just for a special character!)

What a pain! I see what your problem is! My solution will not work and you will probably need help from one of the nerds (A term of endearment) on here that know how to alter the underlying Java if possible.

If you are able to avoid tables and use matrices, I would recommend it after seeing how inflexible they can be.

Answer 2

[Guillaume]

As detailed in the documentation of table You can only use valid Matlab variable names for your table variable names. It can only contain letters, numbers or underscore. One would assume that by letters mathworks means A-Za-z.

So spaces or symbols are not allowed.

Java won't help you there. It's intrinsic to matlab.

[Morten Jensen]

then is there a workaround way to achieve the desired result? I've tried to set up the data in a cell array but having trouble exporting the data due to the limitations of csvwrite

The exported data is to be printed and it is therefore needed to have some clearly defined headers and not just variable names

[Guillaume]

Matlab's high level functions are not particularly good for writing headers to files. You could use xlswrite assuming you have excel installed. Otherwise, you have to use low level functions:

fid = fopen('somefile.txt', 'wt');
fprintf(fid, 'Vol. (ml)\tConc. [wt%]\n');
for row = 1:size(m, 1)
  fprintf(fid, '%f\t%f\n', m(row, 1), m(row, 2));
end
fclose(fid);