| Package | Description | 
|---|---|
| de.lmu.ifi.dbs.elki.math.linearalgebra.pca | 
 Principal Component Analysis (PCA) and Eigenvector processing. 
 | 
| de.lmu.ifi.dbs.elki.math.linearalgebra.pca.weightfunctions | 
 Weight functions used in weighted PCA via  
WeightedCovarianceMatrixBuilder | 
| Modifier and Type | Field and Description | 
|---|---|
protected WeightFunction | 
WeightedCovarianceMatrixBuilder.weightfunction
Holds the weight function. 
 | 
protected WeightFunction | 
WeightedCovarianceMatrixBuilder.Parameterizer.weightfunction  | 
| Constructor and Description | 
|---|
WeightedCovarianceMatrixBuilder(WeightFunction weightfunction)
Constructor. 
 | 
| Modifier and Type | Class and Description | 
|---|---|
class  | 
ConstantWeight
Constant Weight function
 
 The result is always 1.0 
 | 
class  | 
ErfcStddevWeight
Gaussian Error Function Weight function, scaled using stddev. 
 | 
class  | 
ErfcWeight
Gaussian Error Function Weight function, scaled such that the result it 0.1
 at distance == max
 
 erfc(1.1630871536766736 * distance / max)
 
 The value of 1.1630871536766736 is erfcinv(0.1), to achieve the intended
 scaling. 
 | 
class  | 
ExponentialStddevWeight
Exponential Weight function, scaled such that the result it 0.1 at distance
 == max
 
 stddev * exp(-.5 * distance/stddev)
 
 This is similar to the Gaussian weight function, except distance/stddev is
 not squared. 
 | 
class  | 
ExponentialWeight
Exponential Weight function, scaled such that the result it 0.1 at distance
 == max
 
 exp(-2.3025850929940455 * distance/max)
 
 This is similar to the Gaussian weight function, except distance/max is not
 squared 
 | 
class  | 
GaussStddevWeight
Gaussian Weight function, scaled such using standard deviation
 
 factor * exp(-.5 * (distance/stddev)^2)
 
 with factor being 1 / sqrt(2 * PI) 
 | 
class  | 
GaussWeight
Gaussian Weight function, scaled such that the result it 0.1 at distance ==
 max
 
 exp(-2.3025850929940455 * (distance/max)^2) 
 | 
class  | 
InverseLinearWeight
Inverse Linear Weight Function. 
 | 
class  | 
InverseProportionalStddevWeight
Inverse proportional weight function, scaled using the standard deviation.
 
 1 / (1 + distance/stddev) 
 | 
class  | 
InverseProportionalWeight
Inverse proportional weight function, scaled using the maximum.
 
 1 / (1 + distance/max) 
 | 
class  | 
LinearWeight
Linear weight function, scaled using the maximum such that it goes from 1.0
 to 0.1
 
 1 - 0.9 * (distance/max) 
 | 
class  | 
QuadraticStddevWeight
Quadratic weight function, scaled using the standard deviation. 
 | 
class  | 
QuadraticWeight
Quadratic weight function, scaled using the maximum to reach 0.1 at that
 point.
 
 1.0 - 0.9 * (distance/max)^2 
 |