clf
t=0:0.1:3*%pi;
param3d(cos(t),sin(t),0*t);
p=get("hdl"); p.foreground=2;
param3d(0*t,cos(t),sin(t));
p=get("hdl"); p.foreground=2;
param3d(cos(t),0*t,sin(t));
p=get("hdl"); p.foreground=2;

gamma=%pi/6;
param3d(sin(gamma)*cos(t),sin(gamma)*sin(t),cos(gamma)*cos(t));
p=get("hdl"); p.foreground=5;

gamma=%pi/12;
param3d(sin(gamma)*cos(t),sin(gamma)*sin(t),cos(gamma)*cos(t));
p=get("hdl"); p.foreground=5;

title('Bigon, two sided spherical geodesic polygon','fontsize',4);
a=gca(); a.box="off"; a.isoview="on";
tmp=a.x_ticks; tmp.labels=[]; tmp.locations=[];
a.x_ticks=tmp; xlabel("");
a.y_ticks=tmp; ylabel("");
a.z_ticks=tmp; zlabel("");
a.axes_visible=["off","off","off"];
xs2pdf(0,'bigon.pdf');
