what does a = T(m:m, 'label'); mean?

For each iteration, shown in the code below, I want to read the specified file starting from line 12; from line 12, I want to read one line per iteration. I will have 12 iterations in total represented by m., i.e. the first iteration, I want to read one line down from line 12, the second iteration I want to read the second line down from line 12 and so on until the last iteration where I read the 12th line down from line 12. 'H_Ghhor' and 'H_Gkhor' are the header labels for the columns I want to read.

for m=1:length(months) %loop 12 times for the 12 months
    for o=1:length(orientation) %loop 2 times for south and east
        for t=1:length(tilt)       %loop 10 times for the 10 tilting possibilities
            for r = 1:length(row) %loop 3 times for the 3 rows
                if o==1 %if south, get the file with an 'S' in the file name
                    tempFileName = sprintf('t%d_r%d_S-mon.txt',t,r);
                elseif o==2 %if east, get the file with an 'E' in the file name
                    tempFileName = sprintf('t%d_r%d_E-mon.txt',t,r);
                end
                
                File_from_Meteo = append(pathResults, tempFileName); %Combine path and file name 
                T = readtable(File_from_Meteo, 'Headerlines', 12); %table starts at line 12
                
                if t==1 
                    subset = T(m:m, 'H_Ghhor');   
                else
                    subset = T(m:m,'H_Gkhor');
                end
                Res_irr=table2array(subset); %the value of irr for a given m,o,r and t
                
            end
        end
    end
end

My question is:

what does the line

subset = T(m:m, 'H_Ghhor');

exactly mean, and does it fulfil what I described above?

Answer 1

[Stephen23]

"what does a = T(m:m, 'label'); mean?"

It refers to row m of variable/column "label" of the table T, returning a table:

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-table.html

https://www.mathworks.com/help/matlab/tables.html

The colon is not required. It seems that the author of that code also did not realize that they can access the data directly using curly braces (thus avoiding returning a table which then requires the superfluous TABLE2ARRAY):

subset = T{m,'H_Ghhor'};
%         ^           ^ curly braces!

The robust, recommended, and OS-independent alternative to APPEND is to use FULLFILE.

"does it fulfil what I described above?"

It seems to do something like that. Usually it is more efficient to import data before the loop.

[Hannah]

Thank you for the explanation. I removed the colon and implemented the curly braces, so now my code is much better. :D