How do you open .csv files?

For my dissertation, my data is in a .csv file format, yet I've tried using this code to read in data. I don't understand what is going wrong. Matlab says there is a problem with the usage line, but what? The other I have done is put the name of the file. Could anyone solve my simple problem.

if (nargin ~= 1 ) usage(); end

fd = fopen(fname,'data.csv');

if (fd == -1)
  msg = sprintf('File %s not opened\n',fname);
  disp(msg);
  return;
end

[Thomas]

what is usage()? is it a user function?

Answer 1

[Thomas]

Just try

fname='data.csv'
fd = fopen(fname);

if (fd == -1)
  msg = sprintf('File %s not opened\n',fname);
  disp(msg);
  return;
end

If such a file (data.csv) does not exist in the directory then you will get the error message as return