# desolve_system_rk4 vs desolve_odeint

I am getting different results (a result vs no result) from desolve_system_rk4 and desolve_odeint for the same system. What am I missing? My code is the following:

```
reset()
from sage.calculus.desolvers import desolve_system_rk4,desolve_odeint
var('eta,r,ph');
drdt=-sqrt(2.0*r + 200.0 / r - 100.0)*(r - 2.0) / (r^2)
dphdt=10.0*(r - 2.0) / (r^3)
sol1=desolve_system_rk4([drdt,dphdt],[r,ph],ics=[0,4.0,0.3],ivar=eta,end_points=1000,step=0.01)
sol2=desolve_odeint([drdt,dphdt],[4.0,0.3],srange(0,1000,0.01),[r,ph])
D=[[j*cos(k),j*sin(k)] for i,j,k in sol1]
p1=list_plot(D,aspect_ratio=1)
p2=line(zip(sol2[:,0]*cos(sol2[:,1]),sol2[:,0]*sin(sol2[:,1])))
show(graphics_array([p1,p2]))
```