MATLAB: Continue in a for loop if a file isn’t present

for looploops

I'm having a problem with the correct syntax to complete the task without receiving an error. Any help is most appreciated!

In my program there is a for loop to import a series of spreadsheets into Matlab. These spreadsheets are for every US baseball team.

I want to know the syntax of how to skip and continue the for loop if one of the files within the loop are not found in the folder.

Here is the code i have so far:

for Str = {'Diamondbacks' 'Braves' 'Orioles' 'Boston' 'Cubs' 'WhiteSox' 'Reds' 'Indians' 'Rockies' 'Tigers' 'Astros' 'Royals' 'Angels' 'Dodgers' 'Marlins' 'Brewers' 'Twins' 'Mets' 'Yankees' 'Athletics' 'Phillies' 'Pirates' 'Padres' 'Giants' 'Mariners' 'Cardinals' 'Rays' 'Rangers' 'BlueJays' 'Nationals'};
folder = '';
   fileToRead1 = [Str{1} '.xls'];
   sheetName='Sheet1';
 // this is to organize the data in a way easy for me to use 
     [numbers, strings, raw] = xlsread(fileToRead1, sheetName);
  if ~isempty(numbers)
      newData1.data =  numbers;
  end
if ~isempty(strings) && ~isempty(numbers)
    [strRows, strCols] = size(strings);
    [numRows, numCols] = size(numbers);
    likelyRow = size(raw,1) - numRows;
    % Break the data up into a new structure with one field per column.
    if strCols == numCols && likelyRow > 0 && strRows >= likelyRow
        newData1.colheaders = strings(likelyRow, :);
    end
// Here is my feeble attempt to skip and continue the forloop if a file is
// not found.  It doesn't work of course.  
if ~isempty(fileToRead1)
    newData1.data =  numbers;
continue  
end
end

Best Answer

Continue if the file is not there:

if exist(fileToRead1, 'file') == 0
  % File does not exist
  % Skip to bottom of loop and continue with the loop
  continue;
end

Related Solutions

MATLAB: How Can I Write a Matrix to excel using ActXserver (or another way if needed!)

See my demo:

% Demo macro to write numerical arrays and cell arrays
% to two different worksheets in an Excel workbook file.
% Uses xlswrite1, available from the File Exchange
% http://www.mathworks.com/matlabcentral/fileexchange/10465-xlswrite1
function ExcelDemo
clc;
close all;
clear all;
fullFileName = GetXLFileName();
if isempty(fullFileName)
  % User clicked Cancel.

  return;
end
Excel = actxserver('Excel.Application');   
% Prepare proper filename extension.
% Get the Excel version because if it's version 11 (Excel 2003) the file extension should be .xls,
% but if it's 12.0 (Excel 2007) then we'll need to use an extension of .xlsx to avoid nag messages.
excelVersion = str2double(Excel.Version);
if excelVersion < 12
  excelExtension = '.xls';
else
  excelExtension = '.xlsx';
end
% Determine the proper format to save the files in.  It depends on the extension (Excel version).
switch excelExtension
  case '.xls' %xlExcel8 or xlWorkbookNormal
     xlFormat = -4143;
  case '.xlsb' %xlExcel12
     xlFormat = 50;
  case '.xlsx' %xlOpenXMLWorkbook
     xlFormat = 51;
  case '.xlsm' %xlOpenXMLWorkbookMacroEnabled 
     xlFormat = 52;
  otherwise
     xlFormat = -4143;
end
if ~exist(fullFileName, 'file')
  message = sprintf('I am going to create Excel workbook:\n\n%s\n\nClick OK to continue.\nClick Exit to exit this function', fullFileName);
  button = questdlg(message, 'Creating new workbook', 'OK', 'Exit', 'OK');
  drawnow;  % Refresh screen to get rid of dialog box remnants.
  if strcmpi(button, 'Exit')
    return;
  end
  % Add a new workbook.
  ExcelWorkbook = Excel.workbooks.Add;
  % Save this workbook we just created.
  ExcelWorkbook.SaveAs(fullFileName, xlFormat);
  ExcelWorkbook.Close(false);
else
  % Delete the existing file.
  delete(fullFileName);
end
% Open up the workbook named in the variable fullFileName.
invoke(Excel.Workbooks,'Open', fullFileName);
Excel.visible = true;
% Create some sample data.
myData = magic(20);
myOtherData = rand(10);
% Then run the new xlswrite1 function as many times as needed or in a loop 
% (for example xlswrite1(fullFileName, yourArrayName, XL_CellLocation). 
% IMPORTANT NOTE: the Excel object variable MUST exist in the routine that calls xlswrite1()
% and it MUST be named "Excel" EXACTLY because xlswrite1() has this line it it:
%   Excel = evalin('caller', 'Excel');
xlswrite1(fullFileName, myData, 'mySheetName', 'B2');
ca = {'Column Header 1', 'Column Header 2'};
xlswrite1(fullFileName, ca, 'mySheetName', 'B1');
ca = {'Row Header 1'; 'Row Header 2'};
xlswrite1(fullFileName, ca, 'mySheetName', 'A2');
xlswrite1(fullFileName, myOtherData, 'myOtherSheetName', 'B2');
% Delete all empty sheets in the active workbook.
DeleteEmptyExcelSheets(Excel);
% For fun, add comments to cells A1:A12 on sheet #1.
worksheets = Excel.sheets;
thisSheet = get(worksheets, 'Item', 1); 
for k = 1 : 12
  myComment = sprintf('Comment for cell A%d', k);
  cellReference = sprintf('A%d', k);
  theCell = thisSheet.Range(cellReference);
  theCell.AddComment(myComment);
end
% Then run the following code to close the activex server:
invoke(Excel.ActiveWorkbook,'Save');
Excel.Quit;
Excel.delete;
clear Excel;
message = sprintf('Done!\nThis Excel workbook has been created:\n%s', fullFileName);
msgbox(message);
% End of main function: ExcelDemo.m -----------------------------
%--------------------------------------------------------------------
% Gets the name of the workbook from the user.
function fullExcelFileName = GetXLFileName()
  fullExcelFileName = [];  % Default.
  % Ask user for a filename.
  FilterSpec = {'*.xls', 'Excel workbooks (*.xls)'; '*.*', 'All Files (*.*)'};
  DialogTitle = 'Save workbook file name';
  % Get the default filename.  Make sure it's in the folder where this m-file lives.
  % (If they run this file but the cd is another folder then pwd will show that folder, not this one.
  thisFile = mfilename('fullpath');
  [thisFolder, baseFileName, ext] = fileparts(thisFile);
  DefaultName = sprintf('%s/%s.xls', thisFolder, baseFileName);
  [fileName, specifiedFolder] = uiputfile(FilterSpec, DialogTitle, DefaultName);
  if fileName == 0
    % User clicked Cancel.
    return;
  end
  % Parse what they actually specified.
  [folder, baseFileName, ext] = fileparts(fileName);
  % Create the full filename, making sure it has a xls filename.
  fullExcelFileName = fullfile(specifiedFolder, [baseFileName '.xls']);
% --------------------------------------------------------------------
% DeleteEmptyExcelSheets: deletes all empty sheets in the active workbook.
% This function looped through all sheets and deletes those sheets that are
% empty. Can be used to clean a newly created xls-file after all results
% have been saved in it.
function DeleteEmptyExcelSheets(excelObject)
%   excelObject = actxserver('Excel.Application');
%   excelWorkbook = excelObject.workbooks.Open(fileName);
  worksheets = excelObject.sheets;
  sheetIdx = 1;
  sheetIdx2 = 1;
  numSheets = worksheets.Count;
  % Prevent beeps from sounding if we try to delete a non-empty worksheet.
  excelObject.EnableSound = false;
  % Loop over all sheets
  while sheetIdx2 <= numSheets
    % Saves the current number of sheets in the workbook
    temp = worksheets.count;
    % Check whether the current worksheet is the last one. As there always
    % need to be at least one worksheet in an xls-file the last sheet must
    % not be deleted.
    if or(sheetIdx>1,numSheets-sheetIdx2>0)
      % worksheets.Item(sheetIdx).UsedRange.Count is the number of used cells.
      % This will be 1 for an empty sheet.  It may also be one for certain other
      % cases but in those cases, it will beep and not actually delete the sheet.
      if worksheets.Item(sheetIdx).UsedRange.Count == 1
        worksheets.Item(sheetIdx).Delete;
      end
    end
    % Check whether the number of sheets has changed. If this is not the
    % case the counter "sheetIdx" is increased by one.
    if temp == worksheets.count;
      sheetIdx = sheetIdx + 1;
    end
    sheetIdx2 = sheetIdx2 + 1; % prevent endless loop...
  end
  excelObject.EnableSound = true;
  return;

MATLAB: How to simplify importing .xls files within a for loop

Replace

[fileToRead1, folder] = uigetfile();

with

folder = '';
fileToRead1 = [Str '.xls'];

Note: I would suggest that "AngelsData.xls" is a confusing name for a variable. It looks too much like a file name. It is a valid variable name, though, meaning "the field named 'xls' in the structure named 'AngelsData'"

Best Answer

Related Solutions

MATLAB: How Can I Write a Matrix to excel using ActXserver (or another way if needed!)

MATLAB: How to simplify importing .xls files within a for loop

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