# No method matching default\_algorithm in SDDEProblem; SDEProblem and DDEProblem work
**URL:** https://discourse.julialang.org/t/no-method-matching-default-algorithm-in-sddeproblem-sdeproblem-and-ddeproblem-work/109749
**Category:** Numerics
**Tags:** differentialequation
**Created:** [February 5, 2024, 4:14pm UTC](https://discourse.julialang.org/t/no-method-matching-default-algorithm-in-sddeproblem-sdeproblem-and-ddeproblem-work/109749 "2024-02-05T16:14:13Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@cjoshliu](https://discourse.julialang.org/u/cjoshliu)
#### Post date: [February 5, 2024, 4:14pm UTC](https://discourse.julialang.org/t/no-method-matching-default-algorithm-in-sddeproblem-sdeproblem-and-ddeproblem-work/109749/1 "2024-02-05T16:14:13Z")
Hi, I tried running the example from the [SDDE solvers documentation](https://docs.sciml.ai/DiffEqDocs/latest/solvers/sdde_solve/)
```julia
using DifferentialEquations
function hayes_modelf(du, u, h, p, t)
τ, a, b, c, α, β, γ = p
du .= a .* u .+ b .* h(p, t - τ) .+ c
end
function hayes_modelg(du, u, h, p, t)
τ, a, b, c, α, β, γ = p
du .= α .* u .+ γ
end
h(p, t) = (ones(1) .+ t);
tspan = (0.0, 10.0)
pmul = [1.0, -4.0, -2.0, 10.0, -1.3, -1.2, 1.1]
padd = [1.0, -4.0, -2.0, 10.0, -0.0, -0.0, 0.1]
prob = SDDEProblem(hayes_modelf, hayes_modelg, [1.0], h, tspan, pmul;
constant_lags = (pmul[1],));
sol = solve(prob, RKMil())
```
and got the error
```julia
MethodError: no method matching default_algorithm(::SDDEProblem{Vector{Float64}, Tuple{Float64, Float64}, Tuple{Float64}, Tuple{}, true, Vector{Float64}, Nothing, SDDEFunction{true, SciMLBase.FullSpecialize, typeof(hayes_modelf), typeof(hayes_modelg), LinearAlgebra.UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, typeof(hayes_modelg), typeof(h), Base.Pairs{Symbol, Union{}, Tuple{}, @NamedTuple{}}, Nothing})
```
which is surprising as the [SDE](https://docs.sciml.ai/DiffEqDocs/stable/tutorials/sde_example/) and [DDE](https://docs.sciml.ai/DiffEqDocs/stable/tutorials/dde_example/) examples work fine. As solve is given `RKMil()`, I’m also unsure why it’s looking for a default algorithm. How might I fix this? Thanks!
> **Output of \`using Pkg; Pkg.status()\`**
>
> ```julia
> Status `~/private/Project.toml`
> [0c46a032] DifferentialEquations v7.12.0
> [7073ff75] IJulia v1.24.2
> [91a5bcdd] Plots v1.40.0
> [6099a3de] PythonCall v0.9.15
>
> ```
> **Output of \`versioninfo()\`**
>
> ```julia
> Julia Version 1.10.0
> Commit 3120989f39b (2023-12-25 18:01 UTC)
> Build Info:
> Official https://julialang.org/ release
> Platform Info:
> OS: macOS (arm64-apple-darwin22.4.0)
> CPU: 8 × Apple M1
> WORD_SIZE: 64
> LIBM: libopenlibm
> LLVM: libLLVM-15.0.7 (ORCJIT, apple-m1)
> Threads: 1 on 4 virtual cores
> Environment:
> JULIA_NUM_THREADS =
>
> ```
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [February 6, 2024, 12:58am UTC](https://discourse.julialang.org/t/no-method-matching-default-algorithm-in-sddeproblem-sdeproblem-and-ddeproblem-work/109749/2 "2024-02-06T00:58:04Z")
You might need to add StochasticDelayDiffEq.jl?
---
### Author:  [@cjoshliu](https://discourse.julialang.org/u/cjoshliu)
#### Post date: [February 6, 2024, 11:25am UTC](https://discourse.julialang.org/t/no-method-matching-default-algorithm-in-sddeproblem-sdeproblem-and-ddeproblem-work/109749/3 "2024-02-06T11:25:46Z")
Thanks, absolute doofus hours on my part. Thought it was just part of DifferentialEquations…
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [February 6, 2024, 10:00pm UTC](https://discourse.julialang.org/t/no-method-matching-default-algorithm-in-sddeproblem-sdeproblem-and-ddeproblem-work/109749/4 "2024-02-06T22:00:27Z")
no that’s our fault. We should reexport it from diffeq