I am trying to use the new Initialization Schemes option of DifferentialEquations.jl
https://diffeq.sciml.ai/dev/solvers/dae_solve/#Initialization-Schemes-1
But I do not know how to access the new methods.
using DifferentialEquations
import DifferentialEquations: ShampineCollocationInit
using Sundials
using Plots
function f(out,du,u,p,t)
out[1] = - 0.04u[1] + 1e4*u[2]*u[3] - du[1]
out[2] = + 0.04u[1] - 3e7*u[2]^2 - 1e4*u[2]*u[3] - du[2]
out[3] = u[1] + u[2] + u[3] - 1.0
end
u₀ = [1.0, 0, 0]
du₀ = [-0.04, 0.04, 0.0]
tspan = (0.0,100000.0)
differential_vars = [true,true,false]
prob = DAEProblem(f,du₀,u₀,tspan,differential_vars=differential_vars)
sol = solve(prob,IDA(initializealg = ShampineCollocationInit))
plot(sol, xscale=:log10, tspan=(1e-6, 1e5), layout=(3,1))
The previous example return the following Error:
WARNING: could not import DifferentialEquations.ShampineCollocationInit into Main
LoadError: UndefVarError: ShampineCollocationInit not defined
Stacktrace:
[1] top-level scope at /home/Documents/test.jl:19
in expression starting at /home/Documents/test.jl:19
What am I doing wrong?