orbit_2_body_trap

function orbit_2_body_trap_10(inter,ic,m1,m2,n,p,name)
    h=(inter(2)-inter(1))/n;

    x1=ic(1);vx1=ic(2);y1=ic(3);vy1=ic(4);
    x2=ic(5);vx2=ic(6);y2=ic(7);vy2=ic(8);

    y(1,:)=[x1 vx1 y1 vy1 x2 vx2 y2 vy2];
    t(1)=inter(1);

    set(gca,'XLim',[-5 5],'YLim',[-5 5],...
    'XTick',[-5 0 5],'YTick',[-5 0 5]);

    sun_h=animatedline('color','y','Marker','.','markersize',50);
    sun_t=animatedline('color','k','LineStyle','-');
    head=animatedline('color','r','Marker','.','markersize',35);
    tail=animatedline('color','b','LineStyle','-');

    v=VideoWriter(name,'MPEG-4');open(v)
    for k=1:n/p
        for i=1:p
            t(i+1)=t(i)+h;
            y(i+1,:)=trapstep(t(i),y(i,:),h,m1,m2);
        end
        frame=getframe;writeVideo(v,frame);
        y(1,:)=y(p+1,:);t(1)=t(p+1);
        clearpoints(head);
        clearpoints(sun_h);
        addpoints(head,y(1,1),y(1,3))
        addpoints(tail,y(1,1),y(1,3))
        addpoints(sun_h,y(1,5),y(1,7))
        addpoints(sun_t,y(1,5),y(1,7))
        drawnow;
    end
    close(v)
end

function y=trapstep(t,x,h,m1,m2)
    z1=ydot(t,x,m1,m2);
    g=x+h*z1;
    z2=ydot(t+h,g,m1,m2);
    y=x+h*(z1+z2)/2;
end

function z=ydot(t,x,m1,m2)
    g=1;
    mg1=m1*g;   mg2=m2*g;

    px1=x(1);py1=x(3);vx1=x(2);vy1=x(4);
    px2=x(5);py2=x(7);vx2=x(6);vy2=x(8);

    dist=sqrt((px2-px1)^2+(py2-py1)^2);

    z=zeros(1,8);

    z(1)=vx1;
    z(2)=(mg2*(px2-px1))/(dist^3);
    z(3)=vy1;
    z(4)=(mg2*(py2-py1))/(dist^3);

    z(5)=vx2;
    z(6)=(mg1*(px1-px2))/(dist^3);
    z(7)=vy2;
    z(8)=(mg1*(py1-py2))/(dist^3);
end

Not enough input arguments.

Error in orbit_2_body_trap_10 (line 2)
    h=(inter(2)-inter(1))/n;