MATLAB: Matlab can’t find files using xlsread

csv filesfile not foundxlsread

Hi,
I'm using a MATLAB script to compile a massive amount of .csv files into one. The script works fine and has run successfully before, but I am having major problems with xlsread returning error messages similar to the following. (I replaced the foldername and filename because they are a little long and also contain some sensitive info)
XLSREAD unable to open file
'C:\Output\foldername\filename.csv'
File
'C:\Output\foldername\filename.csv'
not found.
I have tried adding the folder to the MATLAB path, but afterward I still get this message and also get error messages using excel with a similar file not found. I was wondering if it was a MATLAB problem or another issue.
Using the exist function before returns a nonzero number, but after adding to the path returns 0. Additionally, moving the files to a different directory for some reason allows excel to open the files, but still not matlab.
I am running MATLAB R2014a on a Windows XP Profesional Version 2002 Service Pack 3 using Excel 2010.
EDIT: It turns out there is actually a maximum allowable pathlength in windows, which is around 260. I found 220, but that just might be my version or system.
Reference: http://stackoverflow.com/questions/265769/maximum-filename-length-in-ntfs-windows-xp-and-windows-vista

Best Answer

Excel has nothing to do with it. If exist() says the file is not there, then nothing (including Excel) will be able to find it either. Can't really say much more unless more specifics are given.
You certainly don't want to use Excel anyway to read in "massive" numbers of csv files and combine them into one. It will have to launch and shutdown Excel each time and that will take forever . Your best bet is to simply open them up as text files with fopen() and get lines with fgetl() and transfer them to the single output file with fprintf(). Finally close the files with fclose().
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