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## jAudioFeatureExtractor.AudioFeatures
クラス FeatureExtractor

    java.lang.Object
      jAudioFeatureExtractor.AudioFeatures.FeatureExtractor

直系の既知のサブクラス:
  AreaMoments, BeatHistogram, BeatHistogramLabels, BeatSum, Compactness, FFTBinFrequencies, FractionOfLowEnergyWindows, HarmonicSpectralCentroid, HarmonicSpectralFlux, HarmonicSpectralSmoothness, LPC, LPCRemoved, MagnitudeSpectrum, MetaFeatureFactory, MFCC, Moments, PeakFinder, PowerSpectrum, RelativeDifferenceFunction, RMS, SpectralCentroid, SpectralFlux, SpectralRolloffPoint, SpectralVariability, StrengthOfStrongestBeat, StrongestBeat, StrongestFrequencyVariability, StrongestFrequencyViaFFTMax, StrongestFrequencyViaSpectralCentroid, StrongestFrequencyViaZeroCrossings, ZeroCrossings

    public abstract class FeatureExtractor

extends java.lang.Object

The prototype for feature extractors. Each class that extends this class will extract a particular feature from a window of audio samples. Such classes do not store feature values, only extract them.

Classes that extend this class should have a constructor that sets the three protected fields of this class.

Daniel McEnnis 05-07-05 Added code to allow generic access to feature attributes

Daniel McEnnis 05-08-05 Added setWindow and setParent features following the composite pattern for new features.

作成者:
  Cory McKay

フィールドの概要
`protected FeatureDefinition` | `definition` Meta-data describing a feature.
`protected java.lang.String[]` | `dependencies` The names of other features that are needed in order for a feature to be calculated.
`protected int[]` | `offsets` The offset in windows of each of the features named in the dependencies field.
`protected DataModel` | `parent` If a feature alters its number of dimensions, it needs to be able to notify the holding object that a visible change has occured.

コンストラクタの概要
`FeatureExtractor()`

メソッドの概要
`abstract java.lang.Object` | `clone()` Create an identical copy of this feature.
`abstract double[]` | `extractFeature(double[] samples, double sampling_rate, double[][] other_feature_values)` The prototype function that classes extending this class will override in order to extract their feature from a window of audio.
`java.lang.String[]` | `getDepenedencies()` Returns the names of other features that are needed in order to extract this feature.
`int[]` | `getDepenedencyOffsets()` Returns the offsets of other features that are needed in order to extract this feature.
`java.lang.String` | `getElement(int index)` Function permitting an unintelligent outside function (ie.
`FeatureDefinition` | `getFeatureDefinition()` Returns meta-data describing this feature.
`void` | `setElement(int index, java.lang.String value)` Function permitting an unintelligent outside function (ie.
`void` | `setParent(DataModel parent)` Gives features a reference to the container frame to notify it that features have changed state and need to be redrawn.
`void` | `setWindow(int windowSize)` Function that must be overridden to allow this feature to be set globally by GlobalChange frame.

クラス java.lang.Object から継承されたメソッド
`equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

フィールドの詳細

### definition

    protected FeatureDefinition definition

  Meta-data describing a feature.

### dependencies

    protected java.lang.String[] dependencies

  The names of other features that are needed in order for a feature to be calculated. Will be null if there are no dependencies.

### offsets

    protected int[] offsets

  The offset in windows of each of the features named in the dependencies field. An offset of -1, for example, means that the feature in dependencies with the same indice should be provided to this class's extractFeature method with a value that corresponds to the window prior to the window corresponding to this feature. Will be null if there are no dependencies. This must be null, 0 or a negative number. Positive numbers are not allowed.

### parent

    protected DataModel parent

  If a feature alters its number of dimensions, it needs to be able to notify the holding object that a visible change has occured.

コンストラクタの詳細

### FeatureExtractor

    public FeatureExtractor()

メソッドの詳細

### getFeatureDefinition

    public FeatureDefinition getFeatureDefinition()

  Returns meta-data describing this feature.

  IMPORTANT: Note that a value of 0 in the returned dimensions of the FeatureDefinition implies that the feature dimensions are variable, and depend on the analyzed data.

### getDepenedencies

    public java.lang.String[] getDepenedencies()

  Returns the names of other features that are needed in order to extract this feature. Will return null if no other features are needed.

### getDepenedencyOffsets

    public int[] getDepenedencyOffsets()

  Returns the offsets of other features that are needed in order to extract this feature. Will return null if no other features are needed.

  The offset is in windows, and the indice of the retuned array corresponds to the indice of the array returned by the getDependencies method. An offset of -1, for example, means that the feature returned by getDependencies with the same indice should be provided to this class's extractFeature method with a value that corresponds to the window prior to the window corresponding to this feature.

### extractFeature

    public abstract double[] extractFeature(double[] samples,
                                            double sampling_rate,
                                            double[][] other_feature_values)
                                     throws java.lang.Exception

  The prototype function that classes extending this class will override in order to extract their feature from a window of audio.

  パラメータ:
    `samples` - The samples to extract the feature from.
    `sampling_rate` - The sampling rate that the samples are encoded with.
    `other_feature_values` - The values of other features that are needed to calculate this value. The order and offsets of these features must be the same as those returned by this class's getDependencies and getDependencyOffsets methods respectively. The first indice indicates the feature/window and the second indicates the value.
  戻り値:
    The extracted feature value(s).
  例外:
    `java.lang.Exception` - Throws an informative exception if the feature cannot be calculated.

### getElement

    public java.lang.String getElement(int index)
                                throws java.lang.Exception

  Function permitting an unintelligent outside function (ie. EditFeatures frame) to get the default values used to populate the table's entries. The correct index values are inferred from definition.attribute value.

  パラメータ:
    `index` - which of AreaMoment's attributes should be edited.
  例外:
    `java.lang.Exception`

### setElement

    public void setElement(int index,
                           java.lang.String value)
                    throws java.lang.Exception

  Function permitting an unintelligent outside function (ie. EditFeatures frame) to set the default values used to popylate the table's entries. Like getElement, the correct index values are inferred from the definition.attributes value.

  パラメータ:
    `index` - attribute to be set
    `value` - new value of the attribute
  例外:
    `java.lang.Exception`

### setWindow

    public void setWindow(int windowSize)
                   throws java.lang.Exception

  Function that must be overridden to allow this feature to be set globally by GlobalChange frame.

  パラメータ:
    `windowSize` - the number of windows of offset to be used in calculating this feature
  例外:
    `java.lang.Exception`

### setParent

    public void setParent(DataModel parent)

  Gives features a reference to the container frame to notify it that features have changed state and need to be redrawn.

  パラメータ:
    `parent` - container frame which holds the model for displaying features in the feature display panel.

### clone

    public abstract java.lang.Object clone()

  Create an identical copy of this feature. This permits FeatureExtractor to use the prototype pattern to create new composite features using metafeatures.

  オーバーライド:
    クラス `java.lang.Object` 内の `clone`

概要 | パッケージ | クラス | 階層ツリー | 非推奨 API | 索引 | ヘルプ
前のクラス 次のクラス | フレームあり フレームなし
概要: 入れ子 | フィールド | コンストラクタ | メソッド | 詳細: フィールド | コンストラクタ | メソッド