I have a differential equation `ddf = f/x^2 - df/x - k*f^2/x`

and I’d know `f(0) = 0`

and `df(1) = 1`

. How can I tell DifferentialEquations.jl about those initial conditions?

I think you want a boundary value problem, but that first condition looks problematic since `ddf`

is undefined at `x=0`

. Here is an example solved on `(1.0, 2.0)`

with `f(1)=0`

and `df(2)=1`

:

```
using DifferentialEquations
function f!(du, u, p, t)
du[1] = u[2]
du[2] = u[1]/t^2 - u[2]/t - p*u[1]^2/t
nothing
end
function bc!(residual, u, p, t)
residual[1] = u[1][1] # f(start of tspan) = 0
residual[2] = u[end][2] - 1 # df(end of tspan) = 1
nothing
end
bvp = BVProblem(f!, bc!, [0.0, 0.0], (1.0, 2.0), 1.0)
sol = solve(bvp, GeneralMIRK4(), dt=0.05)
```