my text file is always not opened when i use fopen!!

I am trying to use a fopen command on matlab on a text file, but it always give me a value of -1. and when i try to continue to use textscan it wont let do the work

Answer 1

[Jan]

If fopen cannot open the file, it is either not existing or there is another bug in your code. Check the existence at first:

exist(FileName, 'file')

Do you use an absolute path or rely on the current folder, which could be change by a timer or GUI callback unexpectedly? Prefer absolute paths containing the folder, because this is much safer.

If this does not help, post the relevant part of the code here.

It is useful to display the error message created by fopen:

[fileID, errmsg] = fopen(FileName);
if fileID == -1
  error(['Cannot open file: %s', char(10), '%s', errmsg);
end

[Stephen23]

Note that both error and assert accept an fprintf-style format string:

   [fileID, errmsg] = fopen(FileName);
  assert(fileID>=3,'Cannot open file:\n%s',errmsg)