How to make this code more efficient, and also how to output results to single excel file with multiple sheets?

Hi there,

I have the following code, which admittedly might be horridly inefficient due to my lack of experience with coding and Matlab.

Is there a way to make it run faster and more efficiently? Also, is there a way to consolidate the outputs into one excel file, with each sheet named after the relevant sample? Finally, is there a way to insert headers into the excel file on top of each column?

Thank you in advance!

startingFolder = pwd;               
fprintf('Select the directory containing the Images and Auto analysis \n \n');
RawImages = uigetdir(startingFolder); %Creating the variable from the user selection
addpath(RawImages); %Ensuring matlab will follow the path
files           = dir([RawImages '\AutoAnalysis\*.xml']);
numOfFiles      = numel(files); %Counting number of files in the folder for looping purposes
Settings        = xml2struct([RawImages '\settings.xml']); %Converting XML to structure then accessing the number of the samples from the Settings file
NumOfSamples    = str2double(Settings.Children(20).Children.Data);

for j = 1:NumOfSamples %Getting the manually named test pieces from the settings
        
        TestPieceName = Settings.Children(22).Children((2*j)).Children(4).Children.Data; %Creating a name variable to use when making file and folder names
        Sample = ['Test Piece ' num2str(j) '-' TestPieceName]; 
        TestPiece = zeros(numOfFiles,3); %Making an array to store the variables

    for k = 1:numOfFiles %Grabbing the time and file data from the save file name
        flds    = {'date','bytes','isdir','datenum'}; %Reading time and temp from file
        A       = rmfield(files,flds); %Remove the file information that is unnecessary 
        codes   = struct2cell(A); %Reduces the structure to only the fields required
        codes   = codes'; %Converts the labels in A to the format required
        new         = strsplit(char(codes(k)),'.'); % To remove the file type
        new2        = strsplit(char(new(1)),'-'); % Splits the experimental conditions
        time        = str2double(new2(2));
        alpha       = new2(3);
        alpha       = char(alpha);
        alpha(1)    = [];
        temp        = str2double(alpha);
        TestPiece(k,1) = time;
        TestPiece(k,2) = temp;
        
        file = [ RawImages '\AutoAnalysis\' files(k).name]; % Creating the k-th file name
        DataSet = xml2struct(file); % Converting XML files to structures 
        datasetNum= numel(DataSet.Children);         
       
        testPieceLocation = datasetNum - NumOfSamples + j; %Indexing Height, Area, and Circumference
        
        TestPiece(k,3) = str2double(DataSet.Children(testPieceLocation).Children(end).Children(7).Children.Data); %Height
        TestPiece(k,4) = str2double(DataSet.Children(testPieceLocation).Children(end).Children(10).Children.Data); %Area
        TestPiece(k,5) = str2double(DataSet.Children(testPieceLocation).Children(end).Children(11).Children.Data); %Circumference
        
        initialheight  = TestPiece(1,3);
        initialarea    = TestPiece(1,4);
        initialcirc    = TestPiece(1,5);
        
        TestPiece(k,3) = TestPiece(k,3)/initialheight;
        TestPiece(k,4) = TestPiece(k,4)/initialarea;
        TestPiece(k,5) = TestPiece(k,5)/initialcirc;        
    end
    
    sampleDirectory = fullfile(RawImages); %file creation
    filename = fullfile(sampleDirectory, ['Results.xls']); %Creating the filename to put the excel file in the appropriate folder
    writematrix(TestPiece, filename, 'Sheet', Sample);
    
end

Answer 1

[Image Analyst]

If you make your variable a cell array, you can combine column header strings with numbers.

Since sample changes only within the outer loop, not the inner one, you're overwriting the file on each iteration of the inner loop. It would be better to move the write to after the inner loop but before the end of the outer loop.

If you look at the options for writecell() and writematrix() you'll see how you can use the 'sheet' option to specify a sheet name.

[Teshan Rezel]

Thank you! I've made some changes after looking up the relevant pages.

"If you make your variable a cell array, you can combine column header strings with numbers." May I ask which variable you're referring to please? Would it be TestPiece?

My new code looks like this, if that helps!

startingFolder = pwd;               
fprintf('Select the directory containing the Images and Auto analysis \n \n');
RawImages = uigetdir(startingFolder); %Creating the variable from the user selection
addpath(RawImages); %Ensuring matlab will follow the path
files           = dir([RawImages '\AutoAnalysis\*.xml']);
numOfFiles      = numel(files); %Counting number of files in the folder for looping purposes
Settings        = xml2struct([RawImages '\settings.xml']); %Converting XML to structure then accessing the number of the samples from the Settings file
NumOfSamples    = str2double(Settings.Children(20).Children.Data);

for j = 1:NumOfSamples %Getting the manually named test pieces from the settings
        
        TestPieceName = Settings.Children(22).Children((2*j)).Children(4).Children.Data; %Creating a name variable to use when making file and folder names
        Sample = ['Test Piece ' num2str(j) '-' TestPieceName]; 
        TestPiece = zeros(numOfFiles,3); %Making an array to store the variables

    for k = 1:numOfFiles %Grabbing the time and file data from the save file name
        flds    = {'date','bytes','isdir','datenum'}; %Reading time and temp from file
        A       = rmfield(files,flds); %Remove the file information that is unnecessary 
        codes   = struct2cell(A); %Reduces the structure to only the fields required
        codes   = codes'; %Converts the labels in A to the format required
        new         = strsplit(char(codes(k)),'.'); % To remove the file type
        new2        = strsplit(char(new(1)),'-'); % Splits the experimental conditions
        time        = str2double(new2(2));
        alpha       = new2(3);
        alpha       = char(alpha);
        alpha(1)    = [];
        temp        = str2double(alpha);
        TestPiece(k,1) = time;
        TestPiece(k,2) = temp;
        
        file = [ RawImages '\AutoAnalysis\' files(k).name]; % Creating the k-th file name
        DataSet = xml2struct(file); % Converting XML files to structures 
        datasetNum= numel(DataSet.Children);         
       
        testPieceLocation = datasetNum - NumOfSamples + j; %Indexing Height, Area, and Circumference
        
        TestPiece(k,3) = str2double(DataSet.Children(testPieceLocation).Children(end).Children(7).Children.Data); %Height
        TestPiece(k,4) = str2double(DataSet.Children(testPieceLocation).Children(end).Children(10).Children.Data); %Area
        TestPiece(k,5) = str2double(DataSet.Children(testPieceLocation).Children(end).Children(11).Children.Data); %Circumference
        
        initialheight  = TestPiece(1,3);
        initialarea    = TestPiece(1,4);
        initialcirc    = TestPiece(1,5);
        
        TestPiece(k,3) = TestPiece(k,3)/initialheight;
        TestPiece(k,4) = TestPiece(k,4)/initialarea;
        TestPiece(k,5) = TestPiece(k,5)/initialcirc;        
    end
    
    sampleDirectory = fullfile(RawImages); %file creation
    filename = fullfile(sampleDirectory, ['Results.xls']); %Creating the filename to put the excel file in the appropriate folder
    writematrix(TestPiece, filename, 'Sheet', Sample);
    
end

[Image Analyst]

Yes, TestPiece, but you need to use braces, not parentheses. See the FAQ:

https://matlab.fandom.com/wiki/FAQ#What_is_a_cell_array.3F

[Teshan Rezel]

this worked, thank you very much!