Class InterpolatingMicrosphere
- java.lang.Object
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- org.apache.commons.math3.analysis.interpolation.InterpolatingMicrosphere
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- Direct Known Subclasses:
InterpolatingMicrosphere2D
public class InterpolatingMicrosphere extends java.lang.Object
Utility class for theMicrosphereProjectionInterpolator
algorithm.- Since:
- 3.6
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Nested Class Summary
Nested Classes Modifier and Type Class Description private static class
InterpolatingMicrosphere.Facet
Microsphere "facet" (surface element).private static class
InterpolatingMicrosphere.FacetData
Data associated with eachInterpolatingMicrosphere.Facet
.
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Field Summary
Fields Modifier and Type Field Description private double
background
Background value.private double
darkThreshold
Lowest non-zero illumination.private int
dimension
Space dimension.private double
maxDarkFraction
Maximum fraction of the facets that can be dark.private java.util.List<InterpolatingMicrosphere.Facet>
microsphere
Microsphere.private java.util.List<InterpolatingMicrosphere.FacetData>
microsphereData
Microsphere data.private int
size
Number of surface elements.
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Constructor Summary
Constructors Modifier Constructor Description protected
InterpolatingMicrosphere(int dimension, int size, double maxDarkFraction, double darkThreshold, double background)
Create an unitialiazed sphere.InterpolatingMicrosphere(int dimension, int size, double maxDarkFraction, double darkThreshold, double background, UnitSphereRandomVectorGenerator rand)
Create a sphere from randomly sampled vectors.protected
InterpolatingMicrosphere(InterpolatingMicrosphere other)
Copy constructor.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected void
add(double[] normal, boolean copy)
Replacei
-th facet of the microsphere.private void
clear()
Reset the all thefacets
data to zero.InterpolatingMicrosphere
copy()
Perform a copy.int
getDimension()
Get the space dimensionality.int
getSize()
Get the size of the sphere.private void
illuminate(double[] sampleDirection, double sampleValue, double weight)
Illumination.private double
interpolate()
Interpolation.double
value(double[] point, double[][] samplePoints, double[] sampleValues, double exponent, double noInterpolationTolerance)
Estimate the value at the requested location.
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Field Detail
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microsphere
private final java.util.List<InterpolatingMicrosphere.Facet> microsphere
Microsphere.
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microsphereData
private final java.util.List<InterpolatingMicrosphere.FacetData> microsphereData
Microsphere data.
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dimension
private final int dimension
Space dimension.
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size
private final int size
Number of surface elements.
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maxDarkFraction
private final double maxDarkFraction
Maximum fraction of the facets that can be dark.
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darkThreshold
private final double darkThreshold
Lowest non-zero illumination.
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background
private final double background
Background value.
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Constructor Detail
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InterpolatingMicrosphere
protected InterpolatingMicrosphere(int dimension, int size, double maxDarkFraction, double darkThreshold, double background)
Create an unitialiazed sphere. Sub-classes are responsible for calling theadd(double[]) add
method in order to initialize all the sphere's facets.- Parameters:
dimension
- Dimension of the data space.size
- Number of surface elements of the sphere.maxDarkFraction
- Maximum fraction of the facets that can be dark. If the fraction of "non-illuminated" facets is larger, no estimation of the value will be performed, and thebackground
value will be returned instead.darkThreshold
- Value of the illumination below which a facet is considered dark.background
- Value returned when themaxDarkFraction
threshold is exceeded.- Throws:
NotStrictlyPositiveException
- ifdimension <= 0
orsize <= 0
.NotPositiveException
- ifdarkThreshold < 0
.OutOfRangeException
- ifmaxDarkFraction
does not belong to the interval[0, 1]
.
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InterpolatingMicrosphere
public InterpolatingMicrosphere(int dimension, int size, double maxDarkFraction, double darkThreshold, double background, UnitSphereRandomVectorGenerator rand)
Create a sphere from randomly sampled vectors.- Parameters:
dimension
- Dimension of the data space.size
- Number of surface elements of the sphere.rand
- Unit vector generator for creating the microsphere.maxDarkFraction
- Maximum fraction of the facets that can be dark. If the fraction of "non-illuminated" facets is larger, no estimation of the value will be performed, and thebackground
value will be returned instead.darkThreshold
- Value of the illumination below which a facet is considered dark.background
- Value returned when themaxDarkFraction
threshold is exceeded.- Throws:
DimensionMismatchException
- if the size of the generated vectors does not match the dimension set in the constructor.NotStrictlyPositiveException
- ifdimension <= 0
orsize <= 0
.NotPositiveException
- ifdarkThreshold < 0
.OutOfRangeException
- ifmaxDarkFraction
does not belong to the interval[0, 1]
.
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InterpolatingMicrosphere
protected InterpolatingMicrosphere(InterpolatingMicrosphere other)
Copy constructor.- Parameters:
other
- Instance to copy.
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Method Detail
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copy
public InterpolatingMicrosphere copy()
Perform a copy.- Returns:
- a copy of this instance.
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getDimension
public int getDimension()
Get the space dimensionality.- Returns:
- the number of space dimensions.
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getSize
public int getSize()
Get the size of the sphere.- Returns:
- the number of surface elements of the microspshere.
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value
public double value(double[] point, double[][] samplePoints, double[] sampleValues, double exponent, double noInterpolationTolerance)
Estimate the value at the requested location. This microsphere is placed at the givenpoint
, contribution of the givensamplePoints
to each sphere facet is computed (illumination) and the interpolation is performed (integration of the illumination).- Parameters:
point
- Interpolation point.samplePoints
- Sampling data points.sampleValues
- Sampling data values at the correspondingsamplePoints
.exponent
- Exponent used in the power law that computes the weights (distance dimming factor) of the sample data.noInterpolationTolerance
- When the distance between thepoint
and one of thesamplePoints
is less than this value, no interpolation will be performed, and the value of the sample will just be returned.- Returns:
- the estimated value at the given
point
. - Throws:
NotPositiveException
- ifexponent < 0
.
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add
protected void add(double[] normal, boolean copy)
Replacei
-th facet of the microsphere. Method for initializing the microsphere facets.- Parameters:
normal
- Facet's normal vector.copy
- Whether to copy the given array.- Throws:
DimensionMismatchException
- if the length ofn
does not match the space dimension.MaxCountExceededException
- if the method has been called more times than the size of the sphere.
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interpolate
private double interpolate()
Interpolation.- Returns:
- the value estimated from the current illumination of the microsphere.
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illuminate
private void illuminate(double[] sampleDirection, double sampleValue, double weight)
Illumination.- Parameters:
sampleDirection
- Vector whose origin is at the interpolation point and tail is at the sample location.sampleValue
- Data value of the sample.weight
- Weight.
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clear
private void clear()
Reset the all thefacets
data to zero.
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