class DecisionTreeID3 extends ClassifierInt
The DecisionTreeID3 class implements a Decision Tree classifier using the
ID3 algorithm. The classifier is trained using a data matrix 'x' and a
classification vector 'y'. Each data vector in the matrix is classified into
one of 'k' classes numbered '0, ..., k-1'. Each column in the matrix represents
a feature (e.g., Humidity). The 'vc' array gives the number of distinct values
per feature (e.g., 2 for Humidity).
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new
DecisionTreeID3(x: MatriI, y: VectoI, fn: Array[String], k: Int, cn: Array[String], vc: Array[Int] = null)
- x
the data vectors stored as rows of a matrix
- y
the class array, where y_i = class for row i of the matrix x
- fn
the names for all features/variables
- k
the number of classes
- cn
the names for all classes
- vc
the value count array indicating number of distinct values per feature
Type Members
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final
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def
##(): Int
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def
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final
def
asInstanceOf[T0]: T0
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def
buildTree(path: Path): Node
Extend the tree given a path e.g.
Extend the tree given a path e.g. ((outlook, sunny), ...).
- path
an existing path in the tree ((feature, value), ...)
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def
calcCorrelation: MatriD
Calculate the correlation matrix for the feature vectors 'fea'.
Calculate the correlation matrix for the feature vectors 'fea'. If the correlations are too high, the independence assumption may be dubious.
- Definition Classes
- ClassifierInt
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def
calcCorrelation2(zrg: Range, xrg: Range): MatriD
Calculate the correlation matrix for the feature vectors of Z (Level 3) and those of X (level 2).
Calculate the correlation matrix for the feature vectors of Z (Level 3) and those of X (level 2). If the correlations are too high, the independence assumption may be dubious.
- zrg
the range of Z-columns
- xrg
the range of X-columns
- Definition Classes
- ClassifierInt
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def
classify(z: VectoI): (Int, String, Double)
Given a data vector z, classify it returning the class number (0, ..., k-1) by following a decision path from the root to a leaf.
Given a data vector z, classify it returning the class number (0, ..., k-1) by following a decision path from the root to a leaf. Return the best class, its name and FIX.
- z
the data vector to classify
- Definition Classes
- DecisionTreeID3 → Classifier
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def
classify(xx: MatriI): VectoI
Classify all of the row vectors in matrix 'xx'.
Classify all of the row vectors in matrix 'xx'.
- xx
the row vectors to classify
- Definition Classes
- ClassifierInt
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def
classify(z: VectoD): (Int, String, Double)
Given a new continuous data vector 'z', determine which class it fits into, returning the best class, its name and its relative probability.
Given a new continuous data vector 'z', determine which class it fits into, returning the best class, its name and its relative probability. Override in classes that require precise real values for classification.
- z
the real vector to classify
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def
clone(): AnyRef
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def
crossValidate(nx: Int = 10, show: Boolean = false): Double
Test the accuracy of the classified results by cross-validation, returning the accuracy.
Test the accuracy of the classified results by cross-validation, returning the accuracy. The "test data" starts at 'testStart' and ends at 'testEnd', the rest of the data is "training data'. FIX - should return a StatVector
- nx
the number of crosses and cross-validations (defaults to 10x).
- show
the show flag (show result from each iteration)
- Definition Classes
- Classifier
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def
crossValidateRand(nx: Int = 10, show: Boolean = false): Double
Test the accuracy of the classified results by cross-validation, returning the accuracy.
Test the accuracy of the classified results by cross-validation, returning the accuracy. This version of cross-validation relies on "subtracting" frequencies from the previously stored global data to achieve efficiency. FIX - are the comments correct? FIX - should return a StatVector
- nx
number of crosses and cross-validations (defaults to 10x).
- show
the show flag (show result from each iteration)
- Definition Classes
- Classifier
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def
dataset(f: Int, path: Path): Array[(Int, Int)]
Extract column from matrix, filtering out values rows that are not on path.
Extract column from matrix, filtering out values rows that are not on path.
- f
the feature to consider (e.g., 2 (Humidity))
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final
def
eq(arg0: AnyRef): Boolean
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def
equals(arg0: Any): Boolean
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def
featureSelection(TOL: Double = 0.01): Unit
Perform feature selection on the classifier.
Perform feature selection on the classifier. Use backward elimination technique, that is, remove the least significant feature, in terms of cross- validation accuracy, in each round.
- TOL
tolerance indicating negligible accuracy loss when removing features
- Definition Classes
- ClassifierInt
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def
finalize(): Unit
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def
fit(y: VectoI, yp: VectoI, k: Int = 2): VectoD
Return the quality of fit including 'acc', 'prec', 'recall', 'kappa'.
Return the quality of fit including 'acc', 'prec', 'recall', 'kappa'. Override to add more quality of fit measures.
- y
the actual class labels
- yp
the precicted class labels
- k
the number of class labels
- Definition Classes
- Classifier
- See also
ConfusionMatmedium.com/greyatom/performance-metrics-for-classification-problems-in-machine-learning-part-i-b085d432082b
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def
fitLabel: Seq[String]
Return the labels for the fit.
Return the labels for the fit. Override when necessary.
- Definition Classes
- Classifier
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final
def
flaw(method: String, message: String): Unit
- Definition Classes
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def
frequency(dset: Array[(Int, Int)], value: Int): (Double, VectoD)
Given a feature column (e.g., 2 (Humidity)) and a value (e.g., 1 (High)) use the frequency of occurrence of the value for each classification (e.g., 0 (no), 1 (yes)) to estimate k probabilities.
Given a feature column (e.g., 2 (Humidity)) and a value (e.g., 1 (High)) use the frequency of occurrence of the value for each classification (e.g., 0 (no), 1 (yes)) to estimate k probabilities. Also, determine the fraction of training cases where the feature has this value (e.g., fraction where Humidity is High = 7/14).
- dset
the list of data set tuples to consider (e.g. value, row index)
- value
one of the possible values for this feature (e.g., 1 (High))
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val
fset: Array[Boolean]
the set of features to turn on or off.
the set of features to turn on or off. All features are on by default. Used for feature selection.
- Attributes
- protected
- Definition Classes
- ClassifierInt
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def
gain(f: Int, path: Path): Double
Compute the information gain due to using the values of a feature/attribute to distinguish the training cases (e.g., how well does Humidity with its values Normal and High indicate whether one will play tennis).
Compute the information gain due to using the values of a feature/attribute to distinguish the training cases (e.g., how well does Humidity with its values Normal and High indicate whether one will play tennis).
- f
the feature to consider (e.g., 2 (Humidity))
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final
def
getClass(): Class[_]
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def
hashCode(): Int
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final
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isInstanceOf[T0]: Boolean
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val
m: Int
the number of data vectors in training/test-set (# rows)
the number of data vectors in training/test-set (# rows)
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- protected
- Definition Classes
- ClassifierInt
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val
md: Double
the training-set size as a Double
the training-set size as a Double
- Attributes
- protected
- Definition Classes
- ClassifierInt
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def
mode(a: Array[Int]): Int
Find the most frequent classification.
Find the most frequent classification.
- a
array of discrete classifications
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val
n: Int
the number of features/variables (# columns)
the number of features/variables (# columns)
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- protected
- Definition Classes
- ClassifierInt
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val
nd: Double
the feature-set size as a Double
the feature-set size as a Double
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- protected
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- ClassifierInt
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final
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ne(arg0: AnyRef): Boolean
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def
notify(): Unit
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final
def
notifyAll(): Unit
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def
reset(): Unit
Reset or re-initialize the frequency tables and the probability tables.
Reset or re-initialize the frequency tables and the probability tables.
- Definition Classes
- DecisionTreeID3 → Classifier
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def
shiftToZero(): Unit
Shift the 'x' Matrix so that the minimum value for each column equals zero.
Shift the 'x' Matrix so that the minimum value for each column equals zero.
- Definition Classes
- ClassifierInt
-
def
size: Int
Return the number of data vectors/points in the entire dataset (training + testing),
Return the number of data vectors/points in the entire dataset (training + testing),
- Definition Classes
- ClassifierInt → Classifier
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final
def
synchronized[T0](arg0: ⇒ T0): T0
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def
test(xx: MatriI, yy: VectoI): Double
Test the quality of the training with a test-set and return the fraction of correct classifications.
Test the quality of the training with a test-set and return the fraction of correct classifications.
- xx
the integer-valued test vectors stored as rows of a matrix
- yy
the test classification vector, where 'yy_i = class' for row 'i' of 'xx'
- Definition Classes
- ClassifierInt
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def
test(itest: IndexedSeq[Int]): Double
Test the quality of the training with a test-set and return the fraction of correct classifications.
Test the quality of the training with a test-set and return the fraction of correct classifications.
- itest
indices of the instances considered test data
- Definition Classes
- ClassifierInt → Classifier
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def
test(testStart: Int, testEnd: Int): Double
Test the quality of the training with a test dataset and return the fraction of correct classifications.
Test the quality of the training with a test dataset and return the fraction of correct classifications. Can be used when the dataset is randomized so that the testing/training part of a dataset corresponds to simple slices of vectors and matrices.
- testStart
the beginning of test region (inclusive).
- testEnd
the end of test region (exclusive).
- Definition Classes
- Classifier
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def
toString(): String
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def
train(itest: IndexedSeq[Int]): DecisionTreeID3
Train the decision tree.
Train the decision tree.
- itest
the indices of the instances considered as testing data@param testStart starting index of test region (inclusive) used in cross-validation.
- Definition Classes
- DecisionTreeID3 → Classifier
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def
train(): Classifier
Train the classifier by computing the probabilities from a training dataset of data vectors and their classifications.
Train the classifier by computing the probabilities from a training dataset of data vectors and their classifications. Must be implemented in any extending class. Can be used when the whole dataset is used for training.
- Definition Classes
- Classifier
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def
train(testStart: Int, testEnd: Int): Classifier
Train the classifier by computing the probabilities from a training dataset of data vectors and their classifications.
Train the classifier by computing the probabilities from a training dataset of data vectors and their classifications. Must be implemented in any extending class. Can be used when the dataset is randomized so that the training part of a dataset corresponds to simple slices of vectors and matrices.
- testStart
starting index of test region (inclusive) used in cross-validation
- testEnd
ending index of test region (exclusive) used in cross-validation
- Definition Classes
- Classifier
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def
vc_default: Array[Int]
Return default values for binary input data (value count 'vc' set to 2).
Return default values for binary input data (value count 'vc' set to 2).
- Definition Classes
- ClassifierInt
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def
vc_fromData: Array[Int]
Return value counts calculated from the input data.
Return value counts calculated from the input data. May wish to call 'shiftToZero' before calling this method.
- Definition Classes
- ClassifierInt
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def
vc_fromData2(rg: Range): Array[Int]
Return value counts calculated from the input data.
Return value counts calculated from the input data. May wish to call 'shiftToZero' before calling this method.
- rg
the range of columns to be considered
- Definition Classes
- ClassifierInt
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final
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wait(): Unit
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wait(arg0: Long, arg1: Int): Unit
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