function ypoint=f(t,y)
 ypoint(1)=y(2)
 ypoint(2)=-sin(y(1))
endfunction

t=-5:.01:5;
t0=-5;
xinit()
for i=0:.5:2
 for j=0:.5:2
  z0=[i;j] ;
  z=ode(z0,t0,t,f);
  plot(z(1,:),z(2,:))
//  param3d(t,z(1,:),z(2,:))
 end
end

function ypoint=ff(t,y)
 ypoint(1)=y(2)
 ypoint(2)=-y(1)
endfunction

xinit()
for i=0:.5:2
 for j=0:.5:2
  z0=[i;j] ;
  z=ode(z0,t0,t,ff);
  plot(z(1,:),z(2,:))
//  param3d(t,z(1,:),z(2,:))
 end
end

function ypoint=fff(t,y)
 ypoint(1)=y(2)
 x=y(1)
 ypoint(2)=-(x-x^3/6+x^5/120)
endfunction

xinit()
for i=0:.5:2
 for j=0:.5:2
  z0=[i;j] ;
  z=ode(z0,t0,t,fff);
  plot(z(1,:),z(2,:))
//  param3d(t,z(1,:),z(2,:))
 end
end


