Load a text file containing both numbers and letters

Question

I have a text file that looks like so:

A    B    C
1    2    3

(This is just a minimal example of what I actually have. My actual files are HUGE and vary in number of rows.)

I would like to load in this file into Octave. However, the file contains letters, rather than just numbers. When I'm trying to apply the load function, I get errors, and I guess this is because the load function only accepts numbers. What function should I use instead?

Answer 1

Call fopen, fscanf, and fclose. The format string must be different for lines containing only letters (like '%s\t%s\t%s'), and for those which contain only numbers (like '%g\t%g\t%g'). You can read lines of identical structure with a single fprintf call.

Example file (data.txt):

A        B        C
D        E        F
1        2        3
4        5        6
7        8        9
10       11       12

Suppose that we know in advance that the file contains 3 columns, and 2 lines with characters at the beginning:

fid = fopen('data.txt', 'r');
[x, nx] = fscanf(fid, '%s\t%s\t%s', [3, 2]);
[y, ny] = fscanf(fid, '%g\t%g\t%g', [3, Inf]);
fclose(fid);

The lines with the characters will be in x', and the lines with numbers will be contained by y'.