Error Symbolic calculations could not initiate. Likely there's a function which is not differentiable by SymEngine

Specific Domains Numerics
1

I’m simulating a satellite around the earth, and got error:
Symbolic calculations could not initiate. Likely there's a function which is not differentiable by SymEngine.
I think it’s because it cannot differentiate the -\frac 3 2 power. But how could it fail to differentiate something that simple?

using DifferentialEquations, ParameterizedFunctions

satellite! = @ode_def Satellite begin
    dx = vx
    dy = vy
    dvx = -GM*(x^2+y^2)^(-3//2) * x
    dvy = -GM*(x^2+y^2)^(-3//2) * y
end GM

G = 6.67e-11
M = 5.97e24
elasticity = 1
u0 = [0, 1e7, 5e3, 0]
tspan = (0.0,15.0)
p = [G*M] 

prob = ODEProblem(satellite!, u0, tspan, p)
sol = solve(prob,Tsit5())
1 Like
3

This is why we’ve moved away from SymEngine. However, that warning is completely harmless here since you’re using a non-stiff ODE solver.