## Uses of Interfaceelki.math.linearalgebra.pca.weightfunctions.WeightFunction

• Packages that use WeightFunction
Package Description
elki.math.linearalgebra.pca
Principal Component Analysis (PCA) and eigenvector processing.
elki.math.linearalgebra.pca.weightfunctions
Weight functions used in weighted PCA via WeightedCovarianceMatrixBuilder.
• ### Uses of WeightFunction in elki.math.linearalgebra.pca

Fields in elki.math.linearalgebra.pca declared as WeightFunction
Modifier and Type Field Description
protected WeightFunction WeightedCovarianceMatrixBuilder.Par.weightfunction
Weight function.
protected WeightFunction WeightedCovarianceMatrixBuilder.weightfunction
Holds the weight function.
Constructors in elki.math.linearalgebra.pca with parameters of type WeightFunction
Constructor Description
WeightedCovarianceMatrixBuilder​(WeightFunction weightfunction)
Constructor.
• ### Uses of WeightFunction in elki.math.linearalgebra.pca.weightfunctions

Classes in elki.math.linearalgebra.pca.weightfunctions that implement WeightFunction
Modifier and Type Class Description
class  ConstantWeight
Constant weight function.
class  ErfcStddevWeight
Gaussian Error Function Weight function, scaled using stddev using: $$\text{erfc}(\frac{1}{\sqrt{2}} \frac{\text{distance}}{\sigma})$$.
class  ErfcWeight
Gaussian Error Function Weight function, scaled such that the result it 0.1 when the distance is the maximum using: $$\text{erfc}(1.1630871536766736 \frac{\text{distance}}{\max})$$.
class  ExponentialStddevWeight
Exponential Weight function, scaled using the standard deviation using: $$\sigma \exp(-\frac{1}{2} \frac{\text{distance}}{\sigma})$$.
class  ExponentialWeight
Exponential Weight function, scaled such that the result it 0.1 at distance equal max, so it does not completely disappear using: $$\exp(-2.3025850929940455 \frac{\text{distance}}{\max})$$
class  GaussStddevWeight
Gaussian weight function, scaled using standard deviation $$\frac{1}{\sqrt{2\pi}} \exp(-\frac{\text{dist}^2}{2\sigma^2})$$
class  GaussWeight
Gaussian weight function, scaled such that the result it 0.1 when distance equals the maximum, using $$\exp(-2.3025850929940455 \frac{\text{dist}^2}{\max^2})$$.
class  InverseLinearWeight
Inverse linear weight function using $$.1+0.9\frac{\text{distance}}{\max}$$.
class  InverseProportionalStddevWeight
Inverse proportional weight function, scaled using the standard deviation using: $$1 / (1 + \frac{distance}{\sigma})$$
class  InverseProportionalWeight
Inverse proportional weight function, scaled using the maximum using: $$1 / (1 + \frac{\text{distance}}{\max} )$$
class  LinearWeight
Linear weight function, scaled using the maximum such that it goes from 1.0 to 0.1 using: $$1 - 0.9 \frac{\text{distance}}{\max}$$
class  QuadraticStddevWeight
Quadratic weight function, scaled using the standard deviation: $$\max\{0.0, 1.0 - \frac{\text{dist}^2}{3\sigma^2} \}$$.
class  QuadraticWeight
Quadratic weight function, scaled using the maximum to reach 0.1 at that point using: $$1.0 - 0.9 \frac{\text{dist}^2}{\max^2}\}$$