public class DependentVariableDifferentialEquation extends DependentVariableDerivatives
OrdinaryDifferentialEquationSystem for use with a
NumericalIntegrator. This allows a user to define a function representing a
system of differential equations and integrate it over an independent variable.| Modifier | Constructor and Description |
|---|---|
protected |
DependentVariableDifferentialEquation(DependentVariableDifferentialEquation existingInstance,
CopyContext context)
Initializes a new instance as a copy of an existing instance.
|
|
DependentVariableDifferentialEquation(OrdinaryDifferentialEquationSystem system)
Initializes a new instance based on an
OrdinaryDifferentialEquationSystem. |
| Modifier and Type | Method and Description |
|---|---|
void |
addDerivatives(double x,
double[] y,
DerivativeMode mode,
double[] derivativeArray)
Compute and add the derivatives of the dependent variables to the given
derivativeArray. |
Object |
clone(CopyContext context)
Clones this object using the specified context.
|
boolean |
getIsThreadSafe()
Gets a value indicating whether the methods on this instance are safe to call from
multiple threads simultaneously.
|
OrdinaryDifferentialEquationSystem |
getSystemOfEquations()
Gets the system of equations which define the derivatives of a set of
dependent variables.
|
void |
setSystemOfEquations(OrdinaryDifferentialEquationSystem value)
Sets the system of equations which define the derivatives of a set of
dependent variables.
|
computeDerivatives, computeDerivatives, getDimension, getDimensionForOrder, getOrders, setOrderspublic DependentVariableDifferentialEquation(@Nonnull OrdinaryDifferentialEquationSystem system)
OrdinaryDifferentialEquationSystem.system - The system of equations defining the derivatives of a
set of dependent variables.protected DependentVariableDifferentialEquation(@Nonnull DependentVariableDifferentialEquation existingInstance, @Nonnull CopyContext context)
See ICloneWithContext.clone(CopyContext) for more information about how to implement this constructor
in a derived class.
existingInstance - The existing instance to copy.context - A CopyContext that controls the depth of the copy.ArgumentNullException - Thrown when existingInstance or context is null.public Object clone(CopyContext context)
This method should be implemented to call a copy constructor on the class of the
object being cloned. The copy constructor should take the CopyContext as a parameter
in addition to the existing instance to copy. The copy constructor should first call
CopyContext.addObjectMapping(T, T) to identify the newly constructed instance
as a copy of the existing instance. It should then copy all fields, using
CopyContext.updateReference(T) to copy any reference fields.
A typical implementation of ICloneWithContext:
public static class MyClass implements ICloneWithContext {
public MyClass(MyClass existingInstance, CopyContext context) {
context.addObjectMapping(existingInstance, this);
someReference = context.updateReference(existingInstance.someReference);
}
@Override
public final Object clone(CopyContext context) {
return new MyClass(this, context);
}
private Object someReference;
}
In general, all fields that are reference types should be copied with a call to
CopyContext.updateReference(T). There are a couple of exceptions:
If one of these exceptions applies, the CopyContext should be given an opportunity
to update the reference before the reference is copied explicitly. Use
CopyContext.updateReference(T) to update the reference. If CopyContext.updateReference(T) returns
the original object, indicating that the context does not have a replacement registered,
then copy the object manually by invoking a Clone method, a copy constructor, or by manually
constructing a new instance and copying the values.
alwaysCopy = context.updateReference(existingInstance.alwaysCopy);
if (existingInstance.alwaysCopy != null && alwaysCopy == existingInstance.alwaysCopy) {
alwaysCopy = (AlwaysCopy) existingInstance.alwaysCopy.clone(context);
}
If you are implementing an evaluator (a class that implements IEvaluator), the
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) method shares some responsibilities with the
copy context constructor. Code duplication can be avoided by doing the following:
CopyContext.updateReference(T). You should still call CopyContext.updateReference(T) on any references to
non-evaluators.
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as the last line in the constructor and pass it the
same CopyContext passed to the constructor.
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as normal. See the reference documentation for
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) for more information on implementing that method.
public MyClass(MyClass existingInstance, CopyContext context) {
super(existingInstance, context);
someReference = context.updateReference(existingInstance.someReference);
evaluatorReference = existingInstance.evaluatorReference;
updateEvaluatorReferences(context);
}
@Override
public void updateEvaluatorReferences(CopyContext context) {
evaluatorReference = context.updateReference(evaluatorReference);
}
@Override
public Object clone(CopyContext context) {
return new MyClass(this, context);
}
private Object someReference;
private IEvaluator evaluatorReference;clone in interface ICloneWithContextclone in class DependentVariableDerivativescontext - The context to use to perform the copy.public boolean getIsThreadSafe()
If this property is true, all methods and properties are guaranteed to be thread safe.
Conceptually, an object that returns true for this method acts as if there is a lock
protecting each method and property such that only one thread at a time can be inside any method or
property in the class. In reality, such locks are generally not used and are in fact discouraged. However,
the user must not experience any exceptions or inconsistent behavior that would not be experienced if such
locks were used.
If this property is false, the behavior when using this class from multiple threads
simultaneously is undefined and may include inconsistent results and exceptions. Clients wishing to use
multiple threads should call CopyForAnotherThread.copy(T) to get a separate instance of the
object for each thread.
getIsThreadSafe in interface IThreadAwaregetIsThreadSafe in class DependentVariableDerivatives@Nonnull public final OrdinaryDifferentialEquationSystem getSystemOfEquations()
public final void setSystemOfEquations(@Nonnull OrdinaryDifferentialEquationSystem value)
public void addDerivatives(double x,
double[] y,
@Nonnull
DerivativeMode mode,
double[] derivativeArray)
derivativeArray.
Since the derivativeArray may already contain derivative information from other sources,
do not overwrite existing values but instead add the derivatives of the given mode to
the existing values.addDerivatives in class DependentVariableDerivativesx - The current independent variable value.y - The current dependent variable values.mode - The mode in which to compute the derivatives. Make sure to only compute
and add the derivatives requested by the given mode or it may cause each
derivative to be added more than once.derivativeArray - The derivative array as output.
Upon returning, each element in the array should represent the first derivative
of the corresponding element in the y.