Why is my code not generating any figures, without it giving errors?

I have data from several planar uniaxial tests and want to plot stress-strain figures and put the Young's modulus, which is defined as the slope of the stress-strain graph, in a list that will eventually contain all young's moduli.

I wrote the following code, but matlab did not generate any figures or saved any to my computer:

% Step 1: Define the directory where your text files are located
directory = 'C:\Users\Biologisch';
% Step 2: Get a list of files in the directory
files = dir(directory);
% Define the column indices you want to extract
columnIndices = [1, 2, 3];  % Modify this as per your requirement
% Define custom names for the result lists
listNames = {'Crosshead', 'Load', 'Time'};  % Modify this with your custom names
all_E = [];
% Step 3: Initialize result lists with custom names to store the results for each column
numColumns = numel(columnIndices);
resultLists = cell(1, numColumns);
for i = 1:numColumns
resultLists{i} = [];
end
W0 = 45;               %Breedte begin [mm]
D = 4*10^-3;           %Dikte [mm]
W = 40;                %Breedte eind
Area = (D)*(W0)*10^(-6);
% Number of lines to skip (in this case, 8 lines)
linesToSkip = 8;
% Initialize divisionResultsList as an empty cell array
divisionResultsList = cell(1, length(files));
% Step 4: Iterate over the list of files
set(0, 'DefaultFigureVisible', 'on');
for i = 1:length(files)
filename = files(i).name;
% Step 5: Check if the file is a text file
if endsWith(filename, '.txt')
% Open the text file
fileID = fopen(fullfile(directory, filename));
% Skip the first 8 lines
for j = 1:linesToSkip
fgetl(fileID);
end
% Read the remaining lines using textscan
data = textscan(fileID, '%f');
% Close the file
fclose(fileID);
% Calculation of stress and strain
crossheadColumn = data{columnIndices(1)};
loadColumn = data{columnIndices(2)};
Stress = loadColumn ./ Area;
L0 = crossheadColumn(1);
%calculate strain from crosshead data
Strain_length = (crossheadColumn-L0)/L0;   
Strain_width = (W0-W)/W;
% Store the division results in the divisionResultsList
divisionResultsList{i} = Stress;
p = polyfit(Strain_length,Stress,1);
f = polyval(p,Strain_length);     % To fit the polynomial on the preferred x coordinates
E    = p(1)
all_E = [all_E;E];
%plot stress-strain curve
figure(1)
plot(Strain_length,Stress,'b')
hold on 
plot(Strain_length,f,'r')
xlabel('Strain')
ylabel('Stress [MPa]')
title(['File: ', files(i).name])
legend('Stress-strain curve','Linear fit')
hold off
%save plot to folder
saveas(gcf, fullfile(directory, 'Stress-strain curve', [filename '.png']));
end
end

1.- The MATLAB and Microsoft DOS commanddir both work alike:

Both take all the files in the folder, to build the requested list.

It may be the case that the files . (go 1 level down) and .. (go 1 level up) are also included in the raw list of files that you use.

I had a similar problem time ago and the solution is to exclude files . and ..

Then you can start processing whatever files containing data.

2.- Also, if you share with the readers of your question one file with data, attaching it to the question, or at least a sample of it, then readers will be a assess whether the data in the file is read correctly, or any other point.