BVP Problems
#
SciMLBase.BVProblem
— Type
Defines an BVP problem. Documentation Page: https://docs.sciml.ai/DiffEqDocs/stable/types/bvp_types/
Mathematical Specification of a BVP Problem
To define a BVP Problem, you simply need to give the function and the initial condition which define an ODE:
along with an implicit function bc!
which defines the residual equation, where
is the manifold on which the solution must live. A common form for this is the two-point BVProblem
where the manifold defines the solution at two points:
Problem Type
Constructors
TwoPointBVProblem{isinplace}(f,bc!,u0,tspan,p=NullParameters();kwargs...)
BVProblem{isinplace}(f,bc!,u0,tspan,p=NullParameters();kwargs...)
or if we have an initial guess function initialGuess(t)
for the given BVP, we can pass the initial guess to the problem constructors:
TwoPointBVProblem{isinplace}(f,bc!,initialGuess,tspan,p=NullParameters();kwargs...)
BVProblem{isinplace}(f,bc!,initialGuess,tspan,p=NullParameters();kwargs...)
For any BVP problem type, bc!
is the inplace function:
bc!(residual, u, p, t)
where residual
computed from the current u
. u
is an array of solution values where u[i]
is at time t[i]
, while p
are the parameters. For a TwoPointBVProblem
, t = tspan
. For the more general BVProblem
, u
can be all of the internal time points, and for shooting type methods u=sol
the ODE solution. Note that all features of the ODESolution
are present in this form. In both cases, the size of the residual matches the size of the initial condition.
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.
Fields
-
f
: The function for the ODE. -
bc
: The boundary condition function. -
u0
: The initial condition. Either the initial condition for the ODE as an initial value problem, or aVector
of values for for collocation methods. -
tspan
: The timespan for the problem. -
p
: The parameters for the problem. Defaults toNullParameters
-
kwargs
: The keyword arguments passed onto the solves.
Solution Type
BVProblem
solutions return an ODESolution
. For more information, see the ODE problem definition page for the ODESolution
docstring.