line 0: Can't plot with an empty x range!

[Joan Picanyol i Puig]

Hi,

I'm running:

511,pc,0$ uname -r; octave --version | head -1
5.3-STABLE
GNU Octave, version 2.1.63 (i386-portbld-freebsd5.3).

I'm getting the message in the subject and can't figure out why, since
pasting the pl command that octave shows in the error in a gnuplot
session works ok.

The code is simple enough (the plotting in the attached channel.m):


    lsignal = sign(rand(1,model.n_t) - 0.5);

[...]
        subplot(1, 1, 1); clg; hold off; axis; leg='';
        model.noise = 1; model.fading = 0; model.multipath = 'none';

        [lr, lalpha, lw] = channel(lsignal, 0, -3);
        subplot(2, 2, 1); clg; hold on; 
        plot(t(1:100), lr(1,1:100), 'b'); leg = [leg; 'r'];
        plot(t(1:100), lw(1,1:100), 'g'); leg = [leg; 'w'];
        plot(t(1:100), lsignal(1,1:100), 'rL'); leg = [leg; 's'];
        title('Senyal (r) i soroll (w) SNR=-3dB');
        axis([t(1), t(100), -3*median(lw(1,:)), 3*median(lw(1,:))]);

etc, etc.

Octave shows the gnuplot command:

gnuplot> pl '/var/tmp/oct-WQnjFW' u 1:2 t "" w lines 3
                                                      ^
         line 0: Can't plot with an empty x range!


gnuplot> pl '/var/tmp/oct-296MpL' u 1:2 t "" w lines 3, '/var/tmp/oct-IxhAPE' u 
1:2 t "" w lines 2, '/var/tmp/oct-WYuTBo' u 1:2 t "" w steps 1, 
'/var/tmp/oct-Fjur2Z' u 1:2 t "" w lines 2
                                                                                
                                                                                
                          ^
         line 0: Can't plot with an empty x range!

Octave only gives me this error if the global variable model.dt (which
controls the spacing of 't') is smaller than 10^-7, i.e.: setting it to
0.000001 works, but 0.0000001 doesn't (I need to set it to 1/20MHz).

I need the code to remain Matlab compatible, any workarounds?

tks
-- 
pica

oct-WQnjFW
Description: Text document

init_model.m
Description: Text document

setup_model.m
Description: Text document

verify_channel.m
Description: Text document

channel.m
Description: Text document