GUI - Plotting graph iteratively

Hi everyone, So I have made a GUI that successfully processes images in batch. Part of the processing is that it counts the number of black pixels in the image and also a 'time' for the image. So for example the first image is 0 seconds, second image is 30 seconds, 3rd image is 60 seconds etc.. Now, I have a loop which, as it runs, displays the variable 'black' (Number of black pixels) and 'time' to the command window. How can I get my GUI, during this loop, to plot 'time' vs 'black' and keep adding iteratively to it as the loop goes round? Here is my code so far that happens when I push the pushbutton. The idea is to get the graph drawing in 'real time' as the code runs.

Here is my code so far for when I press 'pushbutton3' which runs the code:

% --- Executes on button press in pushbutton3.                    %MAIN!!
function pushbutton3_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

%The picture interval is entered in editbox2, if not, this error message
%appears.
Interval=str2num(char(get(handles.edit2,'String')));  %Prompt for user to enter camera interval.
if isempty(Interval)
    errordlg('Error, please load pictures to be processed and enter a picture time interval before clicking Run.');
else

%In and out directories chosen by pushbutton1 and pushbutton2
outDir = handles.outDir;

inDir = handles.inDir;

includeSubdirectories = true;

% All extensions that can be read by IMREAD
imreadFormats       = imformats;
supportedExtensions = [imreadFormats.ext];
% Add dicom extensions
supportedExtensions{end+1} = 'dcm';
supportedExtensions{end+1} = 'ima';
supportedExtensions = strcat('.',supportedExtensions);
% Allow the 'no extension' specification of DICOM
supportedExtensions{end+1} = '';

% Create a image data store that can read all these files
imds = datastore(inDir,...
    'IncludeSubfolders', includeSubdirectories,...
    'Type','image',...
    'FileExtensions',supportedExtensions);

h=waitbar(0, 'Please Wait...');
% Process each image using trial_3 (Image Processing toolbox app that let
% me set the HSV thresholds).
for imgInd = 1:numel(imds.Files)
    perc=numel(imds.Files);
    inImageFile  = imds.Files{imgInd};

      % Output has the same sub-directory structure and file extension as
      % input
      outImageFile = strrep(inImageFile, inDir, outDir);

      try
          % Read
          im = imds.readimage(imgInd);
          % Process
          im = trial_3(im);

          % Write
          if(isdicom(inImageFile))
              dicommeta = dicominfo(inImageFile);
              dicomwrite(im, outImageFile, dicommeta, 'CreateMode', 'copy');
          else
              imwrite(im, outImageFile);
          end
          disp(['PASSED:', inImageFile]);

      catch allExceptions
          disp(['FAILED:', inImageFile]);
          disp(getReport(allExceptions,'basic'));
      end
      waitbar(imgInd/perc, h);
      drawnow;
  end
  delete(h);

%Specify the folder where the files (Pictures) live. Chosen by pushbutton2
myFolder=handles.outDir;
%Get a list of all files in the folder with the desired file name pattern.
filePattern=fullfile(myFolder, '*.JPG');
theFiles=dir(filePattern);
caListBoxItems = cell(length(theFiles), 1);
for k=1:length(theFiles)
    baseFileName=theFiles(k).name;
    fullFileName = fullfile(myFolder, baseFileName);
    thisString = fprintf(1, 'Now reading %s', fullFileName);
    fprintf('%s\n', thisString);
    caListBoxItems{k} = thisString;
    OutputFileNames{k} = theFiles(k).name;
    set(handles.listbox2, 'String', OutputFileNames);   %listbox2 will display file names of processed images.
    drawnow;                                % Force immediate screen repaint.
    image=imread(fullFileName);
    white=nnz(image);
    black=(numel(image)-white);
    time=((k-1)*Interval);
    if black>(numel(image)*0.0193);   %if black pixels is more than 1.93% of pixels in image, experiment complete. Value can be altered.
        disp('The experiment is complete at this stage!')
        fprintf('The number of Black Pixels is:');
        disp(numel(image)-white);
        disp('Time of Picture (Secs): ');
        disp((k-1)*Interval);                        %Here, "Interval" is a variable chosen by user (15 secs, 30 secs etc)
        Status = ('Complete');  
    else
        disp('The experiment is not complete yet.')
        fprintf('The number of Black Pixels is:');
        disp(numel(image)-white);
        Status = ('Incomplete');   
    end
    PhotoDetails={fullFileName, black, time, Status};
    Matrix(k,:)=PhotoDetails;                       %Matrix of three variables produced.
    guidata(hObject,handles);
end
end
Header={'Image', 'Number of Black Pixels', 'Time (Seconds)', 'Status'};
xlswrite('PhotoResults', Header, 'Results');
xlRange='A2';
xlswrite('PhotoResults', Matrix, 'Results', xlRange);

Any ideas? I have put axes on my GUI tagged "axes1" but I cant get it to plot! I am thinking I need to create like a database or matrix of data for the variables 'black' and 'time' then plot them? How do I do this? Any help would be greatly appreciated. Many thanks, Ellis

Answer 1

[Geoff Hayes]

Ellis - where in your code do you try to update axes1? You may need to add a drawnow or a brief pause to allow the axes to be updated properly at the end of any iteration.

For example,

 for k=1:1000
    % do something
    % draw something on the axes
    plot(...);
    % force the update to the axes
    drawnow; % or pause(0.1);
 end