XlsWrite keeps overwriting my excel file!

Hi everybody,

My GUI is very nearly complete but I have one last slight issue. Everytime my image processing is complete, my GUI saves the results to an excel file using xlswrite. This works fine, but as I am error checking my code, the situation could arise where the user wants to run the code again to check if the results are right for example. If this happens, the previous excel file is overwritten with the new results. I want my code to ensure a new excel file is made and the old one is not overwritten, how do I do this? Many thanks for taking your time to answer. Here is the section of code in question:

%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 to listbox2.
    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');  
        Date = sprintf(datestr(now));
    else
        disp('The experiment is not complete yet.')
        fprintf('The number of Black Pixels is:');
        disp(numel(image)-white);
        Status = ('Incomplete');   
        Date = sprintf(datestr(now));
    end

      PhotoDetails={fullFileName, black, time, Status, Date};    %Date variable here will save the exact time and date the images were processed in answer to line 228 and 234.
      Matrix(k,:)=PhotoDetails;                       %Matrix of three variables produced.
      guidata(hObject,handles);

end
end
Header={'Image', 'Number of Black Pixels', 'Time (Seconds)', 'Status', 'Date'};  %Headers that will appear in adjacent cells on excel spread. 
xlswrite('PhotoResults', Header, 'Results');
xlRange='A2';
xlswrite('PhotoResults', Matrix, 'Results', xlRange);

[José-Luis]

1. Check if the file already exists: exist(). If it does, create a new one.
2. Or save what you need in another sheet within the existing file: please read the documentation to understand how to do that.

Answer 1

[Sudhanshu Bhatt]

Hi Ellis,

As suggested above you can use the sample code snippet below to save in a new Excel file everytime:

for counter=1:5
    excelFileName = ['myFileName' num2str(counter) '.xlsx']
    xlswrite(excelFileName, 1:10);
end

Also, you can create a new sheet everytime you run the program.See the sample code below on how to do this:

for counter=1:5
      xlswrite('myExcelFile.xlsx', 1:10, ['Sheet' num2str(counter)]);
end

More information on xlswrite can be found int he documentation page below:

xlswrite Documentation

Hope this help !!

Thanks

Sudhanshu Bhatt