DAE Problems

DAE Problems

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:

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

f should be specified as f(du,u,p,t) (or in-place as f(resid,du,u,p,t)). 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


Parameters are optional, and if not given then a NullParameters() singleton will be used which will throw nice errors if you try to index non-existent parameters. Any extra keyword arguments are passed on to the solvers. For example, if you set a callback in the problem, then that callback will be added in every solve call.

For specifying Jacobians and mass matrices, see the DiffEqFunctions page.


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:

#] add DiffEqProblemLibrary
using DiffEqProblemLibrary.DAEProblemLibrary
# load problems
prob = DAEProblemLibrary.prob_dae_resrob
sol = solve(prob,IDA())
Missing docstring.

Missing docstring for DiffEqProblemLibrary.DAEProblemLibrary.prob_dae_resrob. Check Documenter's build log for details.