NonlinearSystem

System Constructors

ModelingToolkit.NonlinearSystem — Type

struct NonlinearSystem <: ModelingToolkit.AbstractSystem

A nonlinear system of equations.

Fields

eqs
Vector of equations defining the system.
states
Unknown variables.
ps
Parameters.
pins
observed
name
Name: the name of the system

systems
systems: The internal systems

default_u0
default_u0: The default initial conditions to use when initial conditions are not supplied in ODEProblem.

default_p
default_p: The default parameters to use when parameters are not supplied in ODEProblem.

Examples

@variables x y z
@parameters σ ρ β

eqs = [0 ~ σ*(y-x),
       0 ~ x*(ρ-z)-y,
       0 ~ x*y - β*z]
ns = NonlinearSystem(eqs, [x,y,z],[σ,ρ,β])

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Composition and Accessor Functions

sys.eqs or equations(sys): The equations that define the nonlinear system.
sys.states or states(sys): The set of states in the nonlinear system.
sys.parameters or parameters(sys): The parameters of the nonlinear system.

Transformations

Applicable Calculation and Generation Functions

calculate_jacobian
generate_jacobian
jacobian_sparsity

Problem Constructors

DiffEqBase.NonlinearProblem — Type

function DiffEqBase.NonlinearProblem{iip}(sys::NonlinearSystem,u0map,
                                          parammap=DiffEqBase.NullParameters();
                                          jac = false, sparse=false,
                                          checkbounds = false,
                                          linenumbers = true, parallel=SerialForm(),
                                          kwargs...) where iip

Generates an NonlinearProblem from a NonlinearSystem and allows for automatically symbolically calculating numerical enhancements.

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