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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=[[jcos(k),jsin(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]))

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()

reset() from sage.calculus.desolvers import desolve_system_rk4,desolve_odeintdesolve_system_rk4,desolve_odeint var('eta,r,ph'); var('eta,r,ph'); drdt=-sqrt(2.0 * r drdt=-sqrt(2.0*r + 200.0 / r - 100.0)*(r - 2.0) / (r^2) dphdt=10.0 * (r (r^2) dphdt=10.0*(r - 2.0) / (r^3)(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]) 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=[[jcos(k),jsin(k)] D=[[j*cos(k),j*sin(k)] for i,j,k in sol1]sol1] p1=list_plot(D,aspect_ratio=1) p1=list_plot(D,aspect_ratio=1)p2=line(zip(sol2[:,0]*cos(sol2[:,1]),sol2[:,0]*sin(sol2[:,1]))) p2=line(zip(sol2[:,0]cos(sol2[:,1]),sol2[:,0]sin(sol2[:,1]))) show(graphics_array([p1,p2]))show(graphics_array([p1,p2]))