Code in loop won't execute

I have a code in a for-loop that only partiallys executes. There's 9 lines (67-76) that only run once, at the end of the loop.

Please help me see what's wrong here?

spreadsheetName='Results.xlsx';

mainDirectory='C:\Users\cs3761\Documents\MATLAB'; % folder with specimen folders
% mainDirectory='C:\Users\am6416\Documents\MATLAB\Help Charles';  % Equivalent main directory on my computer

listing = dir(mainDirectory); % get main directory info

n=numel(listing);

nFolders=sum(horzcat(listing.isdir)); % create identifier for number of folders - this line simply is for a check and is not actually needed

    for i=3:n
       
        if listing(i).isdir == 1 % if the item is a folder - do stuff   
            
            sampleName=listing(i).name; % store a name for the sample
            
            subDirectory=strcat(mainDirectory,'\',sampleName); % create string that is the file path to your folder
            
            fullFilePath=strcat(subDirectory,'\','specimen.dat'); % this variable fullFilePath is used in the call to readtable instead of the generic 'specimen.dat' - specifies which specimen.dat

            % Load data file and rename first 3 columns
            T = readtable(fullFilePath,'NumHeaderLines',15); % Skip first 15 rows
            T = renamevars(T,["Var1","Var2", "Var3"],["Time","Displacement", "Force"]); % Rename first three columns
           
            %             
            % Calculate corrected torque, displacement and force
            T.CorrDisplacement = (T.Displacement)/(cosd(0)); 
            T.CorrForce = (T.Force)/(cosd(0));
            CorrClamp_Radius = 51.5706;  % Calculate this from specific sample clamp and cable
            T.Angular_Rot = (T.CorrDisplacement*360)/(2*pi*CorrClamp_Radius);

            T.Torque = (T.CorrForce)*(CorrClamp_Radius)/1000;
            OverrunTorque = 0.25;   % Overrun torque from standard AID in Nm
            cf1 = 1.08;  % Standard curve correction factor
            cf2 = cf1 + OverrunTorque;
            T.CorrTorque = (T.Torque)-cf2;
            
            % plot hysteresis graph
            figure; % creates new figure for each plot instead of overwriting axes
            grid on % turn on major gridlines
            grid minor % turn on minor gridlines
            
            plot(T.Angular_Rot,T.CorrTorque);
            tit=title(sampleName);
            tit.Interpreter='none'; % turning off the text interpreter will prevent interpretation of underscores as subscript syntax
            xlabel('Angular Rotation (deg)');
            ylabel('Torque(Nm)');

            % Save the input as MATLAB figure
            figureName = strcat(subDirectory, '.png'); 
            saveas(gcf, figureName) % this will place the figure in the subDirectory folder
            
            % Write to excel
            writetable(T,strcat(mainDirectory,'\',spreadsheetName),'Sheet',sampleName,'WriteMode','append') % writes each table to separate sheet of output spreadsheet                       
            
            % MATLAB 2018b equivalent below
            % writetable(T,strcat(mainDirectory,'\',spreadsheetName),'Sheet',sampleName) % writes each table to separate sheet

            % Export figure to excel
            pos=get(gcf,'Position'); % get the figure location and size
            xlsPasteTo(spreadsheetName,sampleName,pos(3),pos(4),'J2');
           
            % Calculate spring rate
            a = T{125:125,{'CorrTorque'}};
            b = T{44:44,{'CorrTorque'}};
            c = T{125:125,{'Angular_Rot'}};
            d = T{44:44,{'Angular_Rot'}};
                
            Spring_Rate = (a-b)/(c-d);
            SR = 'Spring Rate';
         
            writematrix(SR,spreadsheetName,'Range','L28:L28')
            writematrix (Spring_Rate,spreadsheetName,'Range','M28:M28')
           
            else % directory item is not a folder, keep moving   
         end % end if   
      
     end % end for    

[David Hernandez]

Not sure if you are using the right syntax for the line 9 (isdir)

https://www.mathworks.com/help/matlab/ref/isdir.html

Also Mathworks recommend to use 'isfolder' instead, I gues using this function can fix it.

https://www.mathworks.com/help/matlab/ref/isfolder.html

[Charles Sendegeya]

Thanks. Let me look into that.

The script was working well without issue until I added lines 67 to 76.

Answer 1

[Cris LaPierre]

Here, isdir is a field in the structure returned by dir, and not a use of the isdir function (I initially thought the same thing).

If none of the code in your if statement is running, then the condition of your if statement is never true.

I'm not sure the 9 lines only run once. I think the issue is they always write to the same spot in the same spreadsheet, so it may appear it only runs once. What appears in the Results.xlsx is the Spring_Rate of the final loop only.

BTW, you might be interested in this page on Accessing Data in Tables. You can define a,b,c and d this way:

% Calculate spring rate
a = T.CorrTorque(125);
b = T.CorrTorque(44);
c = T.Angular_Rot(125);
d = T.Angular_Rot(44);

[Charles Sendegeya]

Thank you. Good observation. It is likely spring rate is being returned to the same cell and overwriting previous result.

Let me look into that.