If you try the following: octave:53> phi=linspace(0,2*pi); octave:54> patch(sin(phi),cos(phi),'r') octave:55> axis([0 1 0 1]) one would expect that a quarter of a circle should be drawn. It seems that gnuplot drops all points outside of the plotting window, therefore only a segment of a circle is drawn. Can this be handled in gnuplot correctly? Kai