solid drawing

[jomin]

Hallo!
i am not very exper. with octave!

i want to plot a set of data
x = [1,2,3,4,5,...]
y = [1,2,3,4,5]

when i type: plot (x,y,'Linewidth',1,'r-'); nothing happens: it does not draw the solid line; if i change the r- to r* it draws the stars...

what is wrong here?

THX!
octave 3 with gnuplot on ubuntu