RungeKutta

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class RungeKutta(*args)

Runge-Kutta fourth-order method.

Parameters

transitionFunctionFunction

The function defining the flow of the ordinary differential equation. Must have one parameter.

See also

ODESolver

Examples

>>> import openturns as ot
>>> f = ot.SymbolicFunction(['t', 'y0', 'y1'], ['t - y0', 'y1 + t^2'])
>>> phi = ot.ParametricFunction(f, [0], [0.0])
>>> solver = ot.RungeKutta(phi)
>>> Y0 = [1.0, -1.0]
>>> nt = 100
>>> timeGrid = [(i**2.0) / (nt - 1.0)**2.0 for i in range(nt)]
>>> result = solver.solve(Y0, timeGrid)

Methods

getClassName()	Accessor to the object's name.
getId()	Accessor to the object's id.
getName()	Accessor to the object's name.
getShadowedId()	Accessor to the object's shadowed id.
getTransitionFunction()	Transition function accessor.
getVisibility()	Accessor to the object's visibility state.
hasName()	Test if the object is named.
hasVisibleName()	Test if the object has a distinguishable name.
setName(name)	Accessor to the object's name.
setShadowedId(id)	Accessor to the object's shadowed id.
setTransitionFunction(transitionFunction)	Transition function accessor.
setVisibility(visible)	Accessor to the object's visibility state.
solve(*args)	Solve ODE.

__init__(*args)

getClassName()

Accessor to the object’s name.

Returns

class_namestr

The object class name (object.__class__.__name__).

getId()

Accessor to the object’s id.

Returns

idint

Internal unique identifier.

getName()

Accessor to the object’s name.

Returns

namestr

The name of the object.

getShadowedId()

Accessor to the object’s shadowed id.

Returns

idint

Internal unique identifier.

getTransitionFunction()

Transition function accessor.

Returns

transitionFunctionFieldFunction

Transition function.

getVisibility()

Accessor to the object’s visibility state.

Returns

visiblebool

Visibility flag.

hasName()

Test if the object is named.

Returns

hasNamebool

True if the name is not empty.

hasVisibleName()

Test if the object has a distinguishable name.

Returns

hasVisibleNamebool

True if the name is not empty and not the default one.

setName(name)

Accessor to the object’s name.

Parameters

namestr

The name of the object.

setShadowedId(id)

Accessor to the object’s shadowed id.

Parameters

idint

Internal unique identifier.

setTransitionFunction(transitionFunction)

Transition function accessor.

Parameters

transitionFunctionFieldFunction

Transition function.

setVisibility(visible)

Accessor to the object’s visibility state.

Parameters

visiblebool

Visibility flag.

solve(*args)

Solve ODE.

Parameters

initialStatesequence of float

Initial value of the equation

timeGridsequence of float or Mesh of dimension 1

Time stamps, ie values of at which the solution is computed.

Returns

valuesSample

The solution of the equation at grid points.