public abstract class Interpolator extends Object implements IEvaluator
Modifier  Constructor and Description 

protected 
Interpolator(EvaluatorGroup group)
Initializes a new instance.

protected 
Interpolator(Interpolator existingInstance,
CopyContext context)
Initializes a new instance as a copy of an existing instance.

Modifier and Type  Method and Description 

abstract Object 
clone(CopyContext context)
Clones this object using the specified context.

void 
dispose()
Releases any resources associated with this instance.

protected abstract void 
dispose(boolean disposing)
Releases any resources associated with this instance.

abstract TimeIntervalCollection 
getAvailabilityIntervals(TimeIntervalCollection consideredIntervals)
Gets the intervals over which data is available.

IEvaluator 
getCachingWrapper()
Gets a version of this evaluator that caches the previously computed value so that if it is evaluated
twice at the same date the computation is done only once.

EvaluatorGroup 
getGroup()
Gets the group that contains this evaluator.

abstract boolean 
getIsThreadSafe()
Gets a value indicating whether the methods on this instance are safe to call from
multiple threads simultaneously.

abstract int 
getRequiredDataPoints(int degree,
int inputOrder)
Calculates the number of data points needed to interpolate with the desired degree of accuracy.

double[] 
interpolate(double x,
double[] xTable,
double[] yTable,
int yStride,
int inputOrder,
int outputOrder)
Interpolates values using this interpolation algorithm.

abstract double[] 
interpolate(double x,
double[] xTable,
double[] yTable,
int yStride,
int inputOrder,
int outputOrder,
int startIndex,
int length)
Interpolates values using this interpolation algorithm.

double[] 
interpolateWithDegree(double x,
double[] xTable,
double[] yTable,
int degree,
int yStride,
int inputOrder,
int outputOrder)
Interpolates values using this interpolation algorithm.

abstract boolean 
isAvailable(JulianDate date)
Returns
true if valid data is available for this Julian date, otherwise returns false . 
abstract void 
updateEvaluatorReferences(CopyContext context)
Updates the evaluator references held by this object using the referencetoreference
mapping in the specified
CopyContext . 
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
close
protected Interpolator(@Nonnull EvaluatorGroup group)
group
 The group that contains this evaluator.ArgumentNullException
 Thrown when group
is null
.protected Interpolator(@Nonnull Interpolator 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 abstract void updateEvaluatorReferences(CopyContext context)
CopyContext
.
This method is called by EvaluatorGroup
and usually does not need to be
called directly by users. EvaluatorGroup
uses this method to replace references
to shared evaluators with references to caching versions of the evaluators.
To implement this method, call CopyContext.updateReference(T)
on each evaluator reference
held by your evaluator and assign the return value back to the field.
Shows how to implement this method for an evaluator that contains a nested evaluator:
@Override
public final void updateEvaluatorReferences(CopyContext context) {
m_nestedEvaluator = context.updateReference(m_nestedEvaluator);
}
updateEvaluatorReferences
in interface IEvaluator
context
 The context that specifies the reference mapping.public abstract 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:
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
nonevaluators.
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 ICloneWithContext
context
 The context to use to perform the copy.public final void dispose()
dispose
in interface IDisposable
protected abstract void dispose(boolean disposing)
disposing
 true
to release both managed and unmanaged resources;
false
to release only unmanaged resources.public abstract TimeIntervalCollection getAvailabilityIntervals(TimeIntervalCollection consideredIntervals)
getAvailabilityIntervals
in interface IAvailability
consideredIntervals
 The intervals over which availability information is needed. Note that the returned availability
intervals may indicate availability outside of these intervals of consideration.public abstract boolean isAvailable(@Nonnull JulianDate date)
true
if valid data is available for this Julian date, otherwise returns false
.isAvailable
in interface IAvailability
date
 Date for which to check availability.true
if valid data is available for this Julian date, otherwise returns false
.public abstract 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 IThreadAware
public final EvaluatorGroup getGroup()
getGroup
in interface IEvaluator
public final IEvaluator getCachingWrapper()
This method is called by EvaluatorGroup
to create a caching version of an evaluator
that is shared between multiple computations.
To implement this method in your own evaluator, construct and return a caching version of the evaluator's base class.
For example, if your evaluator implements IEvaluator1
directly, return an instance of
CachingEvaluator
. In many cases, such as when implementing a PointEvaluator
this method does not need to be overridden because the default implementation returns an appropriate
caching wrapper already. If you do not want the last value computed by your evaluator to ever be cached, or
if your evaluator does its own caching internally, this method can return this
.
Shows an example implementation in an evaluator that implements IEvaluator1
directly, where T is double.
@Override
public IEvaluator getCachingWrapper() {
return new CachingEvaluator<Double>(this);
}
getCachingWrapper
in interface IEvaluator
this
should be returned by this method.public abstract int getRequiredDataPoints(int degree, int inputOrder)
degree
 The degree of polynomial approximation desired.inputOrder
 The order of the input data.@Nonnull public final double[] interpolate(double x, @Nonnull double[] xTable, @Nonnull double[] yTable, int yStride, int inputOrder, int outputOrder)
The xTable
array should contain one more than the desired interpolation degree.
For example, for a 7th degree interpolation, xTable
should contain 8 elements.
The yTable
array should contain a number of elements equal to:
* * ( + 1)
x
 The independent variable for which the dependent variables will be interpolated.xTable
 The array of independent variables to use to interpolate. The values
in this array must be in increasing order and the same value must not occur twice in the array.yTable
 The array of dependent variables to use to interpolate. For a set of three
dependent values (p,q,w) and their derivatives (dp, dq, dw) at time 1 and time 2 this should be
as follows: {p1, q1, w1, dp1, dq1, dw1, p2, q2, w2, dp2, dq2, dw2}.yStride
 The number of dependent variable values in yTable
corresponding to
each independent variable value in xTable
. If inputOrder
is greater than 0, this is also the number of first derivative values, second derivative
values, etc. corresponding to each value in xTable
.inputOrder
 The number of dependent variable derivatives in yTable
. If this value is 0,
the yTable
is assumed to contain only dependent variable values, with each
yStride
of them corresponding to a single independent variable in the
xTable
. If this value is 1, the yTable
is assumed to
contain not only the dependent variable values but also their derivatives. There are
yStride
dependent variable values followed by yStride
dependent variable first derivatives corresponding to each independent variable value
in xTable
. Similarly if this value is 2, the
yTable
contains dependent variable values, first derivatives, and second derivatives.outputOrder
 The number of derivatives to return. To return just the dependent variable values,
pass 0 for this parameter. To return the first derivatives along with the dependent variable values, pass 1.
To retrieve the second derivatives as well, pass 2. Note that not all interpolation algorithms are capable
of returning second derivative information, and if a higher outputOrder
is requested than the algorithm is able to provide, the highest order derivative
will be returned and the request for the higher order derivatives is ignored.yStride
elements,
each of which is an interpolated dependent variable value. If outputOrder
is 1 or greater, the array contains an additional yStride
elements,
each of which is an interpolated dependent variable first derivative. Lastly, if
outputOrder
is 2 or greater, the array contains another additional
yStride
elements, each of which is an interpolated variable second
derivative. Note that if the interpolation algorithm is not capable of returning the degree of derivative
requested, it will simply return the highest order derivative available.ArgumentNullException
 Thrown when xTable
or yTable
is null
.@Nonnull public abstract double[] interpolate(double x, @Nonnull double[] xTable, @Nonnull double[] yTable, int yStride, int inputOrder, int outputOrder, int startIndex, int length)
The xTable
array should contain one more than the desired interpolation degree.
For example, for a 7th degree interpolation, xTable
should contain 8 elements.
The yTable
array should contain a number of elements equal to:
* * ( + 1)
x
 The independent variable for which the dependent variables will be interpolated.xTable
 The array of independent variables to use to interpolate. The values
in this array must be in increasing order and the same value must not occur twice in the array.yTable
 The array of dependent variables to use to interpolate.
There can be multiple values corresponding to each independent values in xTable
.
For a set of three dependent values (p,q,w) and their derivatives (dp, dq, dw) at time 1 and time 2
this should be as follows: {p1, q1, w1, dp1, dq1, dw1, p2, q2, w2, dp2, dq2, dw2}.yStride
 The number of dependent variable values in yTable
corresponding to
each independent variable value in xTable
. If inputOrder
is greater than 0, this is also the number of first derivative values, second derivative
values, etc. corresponding to each value in xTable
.inputOrder
 The number of dependent variable derivatives in yTable
. If this value is 0,
the yTable
is assumed to contain only dependent variable values, with each
yStride
of them corresponding to a single independent variable in the
xTable
. If this value is 1, the yTable
is assumed to
contain not only the dependent variable values but also their derivatives. There are
yStride
dependent variable values followed by yStride
dependent variable first derivatives corresponding to each independent variable value
in xTable
. Similarly if this value is 2, the
yTable
contains dependent values, first derivatives, and second derivatives.outputOrder
 The number of derivatives to return. To return just the dependent variable values,
pass 0 for this parameter. To return the first derivatives along with the dependent variable values,
pass 1. To retrieve the second derivatives as well, pass 2. Note that not all interpolation algorithms are capable
of returning second derivative information, and if a higher outputOrder
is requested than the algorithm is able to provide, the highest order derivative
will be returned and the request for the higher order derivatives is ignored.startIndex
 The index in xTable
of the first value to use in the interpolation.
The index of the first value in yTable
to use is calculated as:
* * ( + 1)
length
 The number of values to use in the interpolation. This value should be one more than the
desired interpolation degree. For example for 7th degree interpolation, this parameter
should be 8.yStride
elements,
each of which is an interpolated dependent variable value. If outputOrder
is greater than zero, the array contains an additional number of yStride
elements,
for each output order.ArgumentNullException
 Thrown when xTable
or yTable
is null
.@Nonnull public final double[] interpolateWithDegree(double x, @Nonnull double[] xTable, @Nonnull double[] yTable, int degree, int yStride, int inputOrder, int outputOrder)
degree
.
The xTable
array can contain any number of elements, and the appropriate subset
will be selected according to the degree
of interpolation requested. For
example, if degree
is 5, the 6 elements surrounding x
will be used for interpolation. When using LinearApproximation
, the degree should be 1
since it always deals with only 2 elements surrounding x
.
The yTable
array should contain a number of elements equal to:
* * ( + 1)
If insufficient elements are provided
to perform the requested degree of interpolation, the highest possible degree of interpolation
will be performed.
x
 The independent variable for which the dependent variables will be interpolated.xTable
 The array of independent variables to use to interpolate. The values
in this array must be in increasing order and the same value must not occur twice in the array.yTable
 The array of dependent variables to use to interpolate. For a set of three
dependent values (p,q,w) and their derivatives (dp, dq, dw) at time 1 and time 2 this should be
as follows: {p1, q1, w1, dp1, dq1, dw1, p2, q2, w2, dp2, dq2, dw2}.degree
 The degree of interpolation to perform. For Linear Interpolation, this value should be 1.yStride
 The number of dependent variable values in yTable
corresponding to
each independent variable value in xTable
. If inputOrder
is greater than 0, this is also the number of first derivative values, second derivative
values, etc. corresponding to each value in xTable
.inputOrder
 The number of dependent variable derivatives in yTable
. If this value is 0,
the yTable
is assumed to contain only dependent variable values, with each
yStride
of them corresponding to a single independent variable in the
xTable
. If this value is 1, the yTable
is assumed to
contain not only the dependent variable values but also their derivatives. There are
yStride
dependent variable values followed by yStride
dependent variable first derivatives corresponding to each independent variable value
in xTable
. Similarly if this value is 2, the
yTable
contains values, first derivatives, and second derivatives.outputOrder
 The number of derivatives to return. To return just the dependent variable values,
pass 0 for this parameter. To return the first derivatives as well, pass 1. To retrieve the
second derivatives as well, pass 2. Note that not all interpolation algorithms are capable
of returning second derivative information, and if a higher outputOrder
is requested than the algorithm is able to provide, the highest order derivative
will be returned and the request for the higher order derivatives is ignored.yStride
elements,
each of which is an interpolated dependent variable value. If outputOrder
is 1 or greater, the array contains an additional yStride
elements,
each of which is an interpolated dependent variable first derivative. Lastly, if
outputOrder
is 2 or greater, the array contains another additional
yStride
elements, each of which is an interpolated variable second
derivative.