Re: Reading files in Octave

[Ivan Sutoris]

On Wed, Mar 11, 2009 at 5:59 PM, Samuel H. Dupree, Jr.
<address@hidden> wrote:
> I'm running Octave version 3.0.3 under Mac OS 10.4.11 on a Mac PowerPC G4.
> I'm attempting to read a file of spherical harmonic coefficients of the
> form:
>
>  2   0   0.202150907893000000e-03   0.000000000000000000e+00
>  3   0   0.121260448837000000e-04   0.000000000000000000e+00
>  4   0  -0.145383007072000000e-06   0.000000000000000000e+00
>  3   1   0.307082741328000000e-04   0.561066891941000000e-05
>  4   1  -0.717780149806000000e-05   0.294743374914000000e-05
>  2   2   0.223035130900000000e-04   0.000000000000000000e+00
>  3   2   0.488840471683000000e-05   0.168743052295000000e-05
>  4   2  -0.143951838385000000e-05  -0.288437212720000000e-05
>  2   3   0.000000000000000000e+00   0.000000000000000000e+00
>  3   3   0.143603108489000000e-05  -0.334354467700000000e-06
>  4   3  -0.854788154819000000e-07  -0.788967312839000000e-06
>  2   4   0.000000000000000000e+00   0.000000000000000000e+00
>  3   4   0.000000000000000000e+00   0.000000000000000000e+00
>  4   4  -0.154903893130000000e-06   0.564041555720000000e-07
>
> In Fortran I can read and store each of the cosine (Cij) and sine (Sij)
> coefficients using:
>
> read( unit = lulugr, fmt = *, iostat = iret )  i, j, Cl(i,j), Sl(i,j)
>
> In Octave I attempted to do the same thing using fscanf:
>
>  [ j, k, Cl(j+1,k+1), Sl(j+1,k+1), KOUNT ] = fscanf( gravfile, "%i %i %e
> %e", "C" );
>
> Octave returns an error message stating that k is undefined.
>
>
> The questions I have for this list are: (1) what am I doing wrong, and (2)
> how do I get Octave to input data from an ASCII file like the one
> illustrated above?
>
>
> Thanks in advance,
>
> Sam Dupree.

k appears only in indices of left hand variables, the fscanf usage
itself seems to be ok. I don't know much about IO in Fortran, but I
think in Octave you need to go through each line individually with
cycle, this seems to work:

fid = fopen("testdata.txt");
[a1 a2 a3 a4] = fscanf(fid, '%i %i %e %e', 'C');
while (~feof(fid))
        j = a1;
        k = a2;
        Cl(j+1,k+1) = a3;
        Sl(j+1,k+1) = a4;
        [a1 a2 a3 a4] = fscanf(fid, '%i %i %e %e', 'C');
end
fclose(fid);

Regards
Ivan Sutoris