what's a fast way to read ascii data?

[Dr. Johannes Zellner]

Hi,

I'd like to read ascii data like this:

1 2 3 4
5 6 7 8
....
some text
9 10 11 12
13 14 15 16
...
some more text

so esentially, I've some lines and columns of numeric data but sometimes there's also a line of text.

I'm interested mainly in reading the numeric data.

If I do it like this:

        istream = fopen(fname, 'r');
        while -1 != (vstr = fgets(istream))
            items = str2double(vstr);
            if ~isnan(items) && length(items) == 4
                      ....

it is really slow.

Any hints to do this faster?

Johannes