I recalculated with accounting z=0.306:e=2.142521522*EllipticF(sin(P),0..28770946 99), definition areas are 0=P=Pi/2 and 0.5957449715e17=r=0.2877986650e18. r=(0. 1389227423e34*sin(P)^2-0.1678282376e35)/(0.2282241678e18*sin(P)^2-0.2817115471e18). Second analytic slution: ee=2.142521522*EllipticF(sin(P),0.9577177353), rr=(0. 1751864413e34*sin(P)^2)/(0.6087117927e16*sin(P)^2+0.2817115471e18), definition areas are 0=P=Pi/2 and 0=rr=0.6087117927e16. Problem with calculation precession angle per orbit in first parametric formula which gives Imaginary number for P which corresponds aphelion. P=1.57079637-0.1503825754e-4*I,and P=-1.570796327+0.1503825754e-4*I,Maple 9 gives or these 34.01372910 degrees per orbit and 34.04443070 degrees per orbit. Best Regards, Hannu Poropudas, Finland.