textread function parameters help

Data = textread(fullfile(fNames(i).folder, fNames(i).name), '', -1, 'headerlines', 2);

I got this matlab code, however, I can't figure out what ' ', -1 part means. Could anyone help me with that?

Answer 1

[Voss]

As far as I can tell from reading the documentation for textread, those input arguments don't do anything special. They merely explicitly tell textread to do the default stuff ('' means don't skip any particular characters and -1 means read the whole file). It looks like the -1 can be omitted, but the '' (format specifier) needs to remain.

[Walter Roberson]

Using '' as the format is an undocumented option. It causes textread() to examine the first line of input (after any skipped headers) to try to figure out what the format of the file is.

If I recall correctly, when '' is used for the format, and other undocumented parameters are not used, then the inputs must be numeric. At the moment I do not recall whether comma separators are supported in this mode.