How to write data into .txt file

How should i write the AVG and standard deviation data into .txt file?

  d = 'E:\\ \\ DummyFile\\';
    filePattern = fullfile(d, 'Run*');
    file = dir(filePattern)
    n = length(file)
    for k = 1:n
      baseFileName = file(k).name;
      FullFileName = fullfile(d, baseFileName, 'dummy.csv');
      temp = readtable(FullFileName, 'ReadVariableNames' true, 'ReadRowsNames' true);
      x(:, :, k) = temp(:, :);
    end
    %Finding Average and Std
    Avg = mean(x,3);
    Standard_deviation = std(x,0,3)

Answer 1

[Image Analyst]

% Ask for the name of the file that the user wants to save.
startingFolder = pwd % or wherever you want.
defaultFileName = fullfile(startingFolder, '*.*');
[baseFileName, folder] = uiputfile(defaultFileName, 'Specify a file');
if baseFileName == 0
	% User clicked the Cancel button.
	return;
end
fullFileName = fullfile(folder, baseFileName)
% Open file for writing.
fid = fopen(fullFileName, 'wt');
if fid ~= -1
    % Was able to open it successfully, now write stuff into it.
    fprintf(fid, 'Average = %f.\nStandard Deviation = %f.\n', Avg, Standard_deviation);
    fclose(fid);  
else
    errorMessage = sprintf('Error opening %s for output.', fullFileName);
    uiwait(errordlg(errorMessage));
end

[Utsav Dobhi]

d = 'E:\\ \\ DummyFile\\';
    filePattern = fullfile(d, 'Run*');
    file = dir(filePattern)
    n = length(file)
    for k = 1:n
      baseFileName = file(k).name;
      FullFileName = fullfile(d, baseFileName, 'dummy.csv');
      temp = readtable(FullFileName, 'ReadVariableNames' true, 'ReadRowsNames' true);
      for k ==1:
         x = Nan(size(temp,1), size(temp, 2), n);
         rowNames = temp.Properties.RowNames;
         colNames = temp.Properties.VariableNames;
      end
      x(:, :, k) = temp{:, :};
    end
    
    %Finding Average and Std
    Avg = mean(x,3);
    Standard_deviation = std(x,0,3)
    index_val = 1:size(x,3) % gives 1-30 numbers bez its total 30 files
    
    for i=1:size(x,1) %looping over 96 of rows
       for j=1:size(x,2) %looping over 20 of cols
             y(:) = x(i, j, :) 
             p = polyfit(index_val, y, 1)
             slope(i,j) = p(1);
        end
    end
%Convert Calculation back to table format for easier display
    AvgT = array2table(Avg, 'VariableNames', colNames, 'RowNames', rowNames);
    StdT = array2table(standard_deviation, 'VariableNames', colNames, 'RowNames', rowNames);
    SlopeT = array2table(slope, 'VariableNames', colNames, 'RowNames', rowNames);
    
    % Ask for the name of the file that the user wants to save.
startingFolder = d 
defaultFileName = fullfile(startingFolder, '*.*');
[baseFileName, folder] = uiputfile(defaultFileName, 'Specify a file');
if baseFileName == 0
	% User clicked the Cancel button.
	return;
end
fullFileName = fullfile(folder, baseFileName)
% Open file for writing.
fid = fopen(fullFileName, 'wt');
if fid ~= -1
    % Was able to open it successfully, now write stuff into it.
    writetable(AvgT, fullFileName, 'Delimiter', ',', 'WriteRowNames', true);
    writetable(StdT, fullFileName, 'Delimiter', ',', 'WriteRowNames', true);
    writetable(SlopeT, fullFileName, 'Delimiter', ',', 'WriteRowNames', true);
    
    fclose(fid);  
else
    errorMessage = sprintf('Error opening %s for output.', fullFileName);
    uiwait(errordlg(errorMessage));
end
% How should i generate three different files with given one file name. SO i want to create three different output.csv for AVGT, stdT, and SlopeT data. 

[Utsav Dobhi]

How should i generate three different files with given one file name. SO i want to create three different output.csv for AVGT, stdT, and SlopeT data.

[Image Analyst]

Simply change the filename before each call to writetable().

fullFileName = 'AvgT.csv';
writetable(AvgT, fullFileName, 'Delimiter', ',', 'WriteRowNames', true);
fullFileName = 'StdT.csv';
writetable(StdT, fullFileName, 'Delimiter', ',', 'WriteRowNames', true);
fullFileName = 'SlopeT.csv';
writetable(SlopeT, fullFileName, 'Delimiter', ',', 'WriteRowNames', true);

Answer 2

[madhan ravi]

 doc writematrix % after converting your data into a table
 %or 
 doc dlmwrite