append doesnt change line

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Andrew on 26 Jun 2013
i want to open the 33.txt go to the end of the file add the number 4 ,change line and etc etc...
for k=1:1:5;
fid=fopen('C:\Users\Mr Andrew\Desktop\33.txt','a');
fprintf(fid,'4 \n')
what is my error ? my code doesnt change line... thank you

Accepted Answer

Tom on 26 Jun 2013
try adding a carriage return as well:
fprintf(fid,'4 \r\n')
I'd also recommend using fclose(fid) each time you've finished with the file
Tom on 27 Jun 2013
for what it's worth, Jan is correct about this being a Notepad issue - if you just use '\n' and open it within MATLAB, it appears on a new line.

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More Answers (2)

Image Analyst
Image Analyst on 26 Jun 2013
Why is fopen inside the loop? You aren't showing all your real code but chances are that you want it before the loop, not inside it. Also, add an fclose after the loop.

Jan on 26 Jun 2013
The data is written, when the file is closed:
fid = fopen('C:\Users\Mr Andrew\Desktop\33.txt', 'a');
for k = 1:5
fprintf(fid,'4 \n')
fclose(fid); % close the file!
Jan on 27 Jun 2013
Edited: Jan on 27 Jun 2013
The text file created by my program is correct and understood by almost all editors. Only Notepad fails, but this is a problem of Notepad, not of the file.
Bit inserting the \r explicitly causes traoubles under e.g. older versions of XEmacs, the TeX interpreter, Matlab until version 6.5 under Linux, etc. Therefore the most efficient solution is relying on '\n' and omitting the usage of the dull Notepad (Notepad++ from the net is much smarter!).
Another method to create the old DOS linebreaks under Windows: Open the file in text-mode:
fopen(FileName, 'at')
Then fprintf(fid, '\n') writes \r\n autoamtically. But this can have strange side effects, like using the End-Of-File character accidently and the number of characters will differ from the number of bytes.

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