Class BaseAbstractUnivariateIntegrator
- java.lang.Object
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- org.apache.commons.math4.legacy.analysis.integration.BaseAbstractUnivariateIntegrator
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- All Implemented Interfaces:
UnivariateIntegrator
- Direct Known Subclasses:
IterativeLegendreGaussIntegrator
,MidPointIntegrator
,RombergIntegrator
,SimpsonIntegrator
,TrapezoidIntegrator
public abstract class BaseAbstractUnivariateIntegrator extends Object implements UnivariateIntegrator
Provide a default implementation for several generic functions.- Since:
- 1.2
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Field Summary
Fields Modifier and Type Field Description static double
DEFAULT_ABSOLUTE_ACCURACY
Default absolute accuracy.static int
DEFAULT_MAX_ITERATIONS_COUNT
Default maximal iteration count.static int
DEFAULT_MIN_ITERATIONS_COUNT
Default minimal iteration count.static double
DEFAULT_RELATIVE_ACCURACY
Default relative accuracy.protected IntegerSequence.Incrementor
iterations
The iteration count.
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Constructor Summary
Constructors Modifier Constructor Description protected
BaseAbstractUnivariateIntegrator(double relativeAccuracy, double absoluteAccuracy)
Construct an integrator with given accuracies.protected
BaseAbstractUnivariateIntegrator(double relativeAccuracy, double absoluteAccuracy, int minimalIterationCount, int maximalIterationCount)
Construct an integrator with given accuracies and iteration counts.protected
BaseAbstractUnivariateIntegrator(int minimalIterationCount, int maximalIterationCount)
Construct an integrator with given iteration counts.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected double
computeObjectiveValue(double point)
Compute the objective function value.protected abstract double
doIntegrate()
Method for implementing actual integration algorithms in derived classes.double
getAbsoluteAccuracy()
Get the absolute accuracy.int
getEvaluations()
Get the number of function evaluations of the last run of the integrator.int
getIterations()
Get the number of iterations of the last run of the integrator.protected double
getMax()
int
getMaximalIterationCount()
Get the upper limit for the number of iterations.protected double
getMin()
int
getMinimalIterationCount()
Get the min limit for the number of iterations.double
getRelativeAccuracy()
Get the relative accuracy.double
integrate(int maxEval, UnivariateFunction f, double lower, double upper)
Integrate the function in the given interval.protected void
setup(int maxEval, UnivariateFunction f, double lower, double upper)
Prepare for computation.
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Field Detail
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DEFAULT_ABSOLUTE_ACCURACY
public static final double DEFAULT_ABSOLUTE_ACCURACY
Default absolute accuracy.- See Also:
- Constant Field Values
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DEFAULT_RELATIVE_ACCURACY
public static final double DEFAULT_RELATIVE_ACCURACY
Default relative accuracy.- See Also:
- Constant Field Values
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DEFAULT_MIN_ITERATIONS_COUNT
public static final int DEFAULT_MIN_ITERATIONS_COUNT
Default minimal iteration count.- See Also:
- Constant Field Values
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DEFAULT_MAX_ITERATIONS_COUNT
public static final int DEFAULT_MAX_ITERATIONS_COUNT
Default maximal iteration count.- See Also:
- Constant Field Values
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iterations
protected IntegerSequence.Incrementor iterations
The iteration count.
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Constructor Detail
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BaseAbstractUnivariateIntegrator
protected BaseAbstractUnivariateIntegrator(double relativeAccuracy, double absoluteAccuracy, int minimalIterationCount, int maximalIterationCount)
Construct an integrator with given accuracies and iteration counts.The meanings of the various parameters are:
- relative accuracy:
this is used to stop iterations if the absolute accuracy can't be
achieved due to large values or short mantissa length. If this
should be the primary criterion for convergence rather then a
safety measure, set the absolute accuracy to a ridiculously small value,
like
Precision.SAFE_MIN
. - absolute accuracy: The default is usually chosen so that results in the interval -10..-0.1 and +0.1..+10 can be found with a reasonable accuracy. If the expected absolute value of your results is of much smaller magnitude, set this to a smaller value.
- minimum number of iterations: minimal iteration is needed to avoid false early convergence, e.g. the sample points happen to be zeroes of the function. Users can use the default value or choose one that they see as appropriate.
- maximum number of iterations: usually a high iteration count indicates convergence problems. However, the "reasonable value" varies widely for different algorithms. Users are advised to use the default value supplied by the algorithm.
- Parameters:
relativeAccuracy
- relative accuracy of the resultabsoluteAccuracy
- absolute accuracy of the resultminimalIterationCount
- minimum number of iterationsmaximalIterationCount
- maximum number of iterations- Throws:
NotStrictlyPositiveException
- if minimal number of iterations is not strictly positiveNumberIsTooSmallException
- if maximal number of iterations is lesser than or equal to the minimal number of iterations
- relative accuracy:
this is used to stop iterations if the absolute accuracy can't be
achieved due to large values or short mantissa length. If this
should be the primary criterion for convergence rather then a
safety measure, set the absolute accuracy to a ridiculously small value,
like
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BaseAbstractUnivariateIntegrator
protected BaseAbstractUnivariateIntegrator(double relativeAccuracy, double absoluteAccuracy)
Construct an integrator with given accuracies.- Parameters:
relativeAccuracy
- relative accuracy of the resultabsoluteAccuracy
- absolute accuracy of the result
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BaseAbstractUnivariateIntegrator
protected BaseAbstractUnivariateIntegrator(int minimalIterationCount, int maximalIterationCount)
Construct an integrator with given iteration counts.- Parameters:
minimalIterationCount
- minimum number of iterationsmaximalIterationCount
- maximum number of iterations- Throws:
NotStrictlyPositiveException
- if minimal number of iterations is not strictly positiveNumberIsTooSmallException
- if maximal number of iterations is lesser than or equal to the minimal number of iterations
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Method Detail
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getRelativeAccuracy
public double getRelativeAccuracy()
Get the relative accuracy.- Specified by:
getRelativeAccuracy
in interfaceUnivariateIntegrator
- Returns:
- the accuracy
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getAbsoluteAccuracy
public double getAbsoluteAccuracy()
Get the absolute accuracy.- Specified by:
getAbsoluteAccuracy
in interfaceUnivariateIntegrator
- Returns:
- the accuracy
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getMinimalIterationCount
public int getMinimalIterationCount()
Get the min limit for the number of iterations.- Specified by:
getMinimalIterationCount
in interfaceUnivariateIntegrator
- Returns:
- the actual min limit
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getMaximalIterationCount
public int getMaximalIterationCount()
Get the upper limit for the number of iterations.- Specified by:
getMaximalIterationCount
in interfaceUnivariateIntegrator
- Returns:
- the actual upper limit
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getEvaluations
public int getEvaluations()
Get the number of function evaluations of the last run of the integrator.- Specified by:
getEvaluations
in interfaceUnivariateIntegrator
- Returns:
- number of function evaluations
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getIterations
public int getIterations()
Get the number of iterations of the last run of the integrator.- Specified by:
getIterations
in interfaceUnivariateIntegrator
- Returns:
- number of iterations
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getMin
protected double getMin()
- Returns:
- the lower bound.
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getMax
protected double getMax()
- Returns:
- the upper bound.
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computeObjectiveValue
protected double computeObjectiveValue(double point)
Compute the objective function value.- Parameters:
point
- Point at which the objective function must be evaluated.- Returns:
- the objective function value at specified point.
- Throws:
TooManyEvaluationsException
- if the maximal number of function evaluations is exceeded.
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setup
protected void setup(int maxEval, UnivariateFunction f, double lower, double upper)
Prepare for computation. Subclasses must call this method if they theintegrate
method.- Parameters:
maxEval
- Maximum number of evaluations.f
- the integrand functionlower
- the min bound for the intervalupper
- the upper bound for the interval- Throws:
NullArgumentException
- iff
isnull
.MathIllegalArgumentException
- ifmin >= max
.
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integrate
public double integrate(int maxEval, UnivariateFunction f, double lower, double upper)
Integrate the function in the given interval.- Specified by:
integrate
in interfaceUnivariateIntegrator
- Parameters:
maxEval
- Maximum number of evaluations.f
- the integrand functionlower
- the lower bound for the intervalupper
- the upper bound for the interval- Returns:
- the value of integral
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doIntegrate
protected abstract double doIntegrate()
Method for implementing actual integration algorithms in derived classes.- Returns:
- the root.
- Throws:
TooManyEvaluationsException
- if the maximal number of evaluations is exceeded.MaxCountExceededException
- if the maximum iteration count is exceeded or the integrator detects convergence problems otherwise
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