MATLAB Answers

Elaheh
0

How to force a for loop to continue?

Asked by Elaheh
on 2 Aug 2018
Latest activity Edited by Jan
on 27 Jun 2019
Hi, I need to copy data from individual excel files from 33 participants, and paste all in one excel file. I did it for the first sheet and then for the second sheet, etc. The problem is that some of the files have 4 sheets and some have 6 sheets. Also, some of the sheets do not have data. Therefore the script stops when there is no data. How can I force it to continue and report the missing data? The following stops when data doesn't exist.
first_data = true;
for i=2:34
sheet=6;
STIMroot='C:\Users\ski\CloudStation\Zahra\dissertation\data analysis\behavioral data analysis\monolingualSTIM\';
Drop='C:\Users\ski\CloudStation\Zahra\dissertation\data analysis\behavioral data analysis\monolingualSTIM\final.xls';
STIMfile=strcat(STIMroot,num2str(i),'\',num2str(i),'.xls'); %get the STIM file
if exist(STIMfile,'file')
STIMdata = xlsread( STIMfile,sheet);
data2=STIMdata(:,3:5);
if first_data == true;
export_data = data2;
first_data = false;
else
export_data = horzcat(export_data,data2 );
end
else
warningMessage = sprintf('Warning: file does not exist:\n%s',h);
continue;
end
end
xlswrite(Drop,export_data,1);

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1 Answer

Answer by OCDER
on 2 Aug 2018
 Accepted Answer

Use try/catch statements to force a loop to continue due to an unexpected error.
for j = 1:10
try
... your code...
catch
warning('found error in %dth file', j);
continue
end
... your code, if "try" codes succeed
end

  3 Comments

Thank you. What do you mean by this part?
... your code, if "try" codes succeed
OCDER
on 3 Aug 2018
Oh, I just meant that you can use try/catch flexibly to do different things for different function errors.
%EXAMPLE 1
try
doThis %Try this, if it fails, no fatal error
catch
continue
end
doThis2; %doThis succeeded, but if doThis2 errors, make it a fatal error.
%EXAMPLE 2
try
doThis %Try this, if it fails, no fatal error
doThis2; %If this errors, it's no longer a fatal error.
catch
continue
end
Jan
on 27 Jun 2019
Some programmers avoid continue for reasons of clarity. The code can be written without it also:
for j = 1:10
try
... your code...
... your code, if "try" codes succeed
catch ME
warning('found error in %dth file: %s', j, ME.message);
end
end

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