with(plots): k1:=1/sqrt(2); fsolve(JacobiSN(u,k1)=1,u); plot({JacobiSN(u,k1),JacobiCN(u,k1),JacobiDN(u,k1)}, > u=-1.854074677..3*1.854074677); delau:=[-a*(1-epsilon)*(EllipticK(kk)+ > EllipticF(JacobiSN(u,kk),kk))-a*(1+epsilon)* > (EllipticE(kk)+EllipticE(JacobiSN(u,kk),kk)),a*(1+epsilon)* > JacobiDN(u,kk)*cos(v),a*(1+epsilon)*JacobiDN(u,kk)*sin(v)]; with(plots): plotund:=proc(a,eps,theta,phi) > local kk,uu; > kk:=2*sqrt(eps)/(1+eps); > uu:=fsolve(JacobiSN(u,kk)=1,u); > plot3d(subs({u=u(t),v=v(t)},[-a*(1-eps)*(EllipticK(kk)+ > EllipticF(JacobiSN(u,kk),kk))-a*(1+eps)*(EllipticE(kk)+ > EllipticE(JacobiSN(u,kk),kk)),a*(1+eps)*JacobiDN(u,kk)* > cos(v),a*(1+eps)*JacobiDN(u,kk)*sin(v)]),u=-uu..uu,v=0..2*Pi, > scaling=constrained,axes=boxed,orientation=[theta,phi], > shading=XY,lightmodel=light3); > end: plotund(1,0.7,-79,70); plotund(1,0.3,-65,70); EFG(subs(kk=2*sqrt(epsilon)/(1+epsilon),delau));