Question

I am passing in a variable name MetabMapString to the function spectroscopy(). MetabMapString is the name of the field I want to call. But It seems as if Matlab is thiking that MetabMapString is the name of the fields cause it returns that there is no field names MetabMapString. I have included some code. Is there a way to get this to work?

function spectroscopy(MetabMapString)
    spect = importdata(spectLCMI);
    n = length(spect.MetabMapString);

    Row = spect.Row;
    Col = spect.Col;
    spectOrig = spect.MetabMapString;

    ...

end

Here is the error

??? Reference to non-existent field 'MetabMapString'.

Error in ==> SpectDraw>spectroscopy at 1165
n = length(spect.MetabMapString);

Answer 1

It should be:

n = length(spect.(MetabMapString));

That should work. Same in all other places where you’re using a variable which contains a string as a field name of a struct or MATLAB class, or as a method name of a class:

spectOrig = spect.(MetabMapString);