DAE Types

Mathematical Specification of an DAE Problem

To define a DAE Problem, you simply need to give the function $f$ and the initial condition $u₀$ which define an ODE:

\[0 = f(t,u,du)\]

f should be specified as f(t,u,du) (or in-place as f(t,u,du,resid)). Note that we are not limited to numbers or vectors for u₀; one is allowed to provide u₀ as arbitrary matrices / higher dimension tensors as well.

Problem Type

Constructors

DAEProblem(f,u0,du0,tspan) : Defines the ODE with the specified functions.

Fields

f: The function in the ODE.
u0: The initial condition.
du0: The initial condition for the derivative.
tspan: The timespan for the problem.
callback: A callback to be applied to every solver which uses the problem. Defaults to a black CallbackSet, which will have no effect.

Special Solver Options

Special Solution Fields

du: The saved derivative values.

Example Problems

Examples problems can be found in DiffEqProblemLibrary.jl.

To use a sample problem, such as prob_dae_resrob, you can do something like:

#Pkg.add("DiffEqProblemLibrary")
using DiffEqProblemLibrary
prob = prob_dae_resrob
sol = solve(prob,IDA())