Packages

class LDA extends ClassifierReal

The LDA class implements a Linear Discriminant Analysis 'LDA' classifier. It places a vector into a group according to its maximal discriminant function. FIX - currently only works when the number of classes 'k' = 2.

See also

en.wikipedia.org/wiki/Linear_discriminant_analysis

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  1. LDA
  2. ClassifierReal
  3. Classifier
  4. Model
  5. ConfusionFit
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  7. QoF
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Instance Constructors

  1. new LDA(x: MatriD, y: VectoI, fn_: Strings = null, k: Int = 2, cn_: Strings = null, hparam: HyperParameter = null)

    x

    the real-valued training/test data vectors stored as rows of a matrix

    y

    the training/test classification vector, where y_i = class for row i of the matrix x

    fn_

    the names for all features/variables

    k

    the number of classes (k in {0, 1, ...k-1}

    cn_

    the names for all classes

    hparam

    the hyper-parameters

Value Members

  1. def accuracy: Double

    Compute the accuracy of the classification, i.e., the fraction of correct classifications.

    Compute the accuracy of the classification, i.e., the fraction of correct classifications. Note, the correct classifications 'tp_i' are in the main diagonal of the confusion matrix.

    Definition Classes
    ConfusionFit
  2. 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
    ClassifierReal
  3. 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
    ClassifierReal
  4. def classify(z: VectoD): (Int, String, Double)

    Classify vector 'z' by computing its discriminant function 'f' for each group and return the group index with the maximun value for 'f'.

    Classify vector 'z' by computing its discriminant function 'f' for each group and return the group index with the maximun value for 'f'.

    z

    the real vector to classify

    Definition Classes
    LDAClassifier
  5. def classify(xx: MatriD = x): 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 (defaults to x)

    Definition Classes
    ClassifierReal
  6. def classify(z: VectoI): (Int, String, Double)

    Given a new discrete (integer-valued) data vector 'z', determine which class it belongs to, by first converting it to a vector of doubles.

    Given a new discrete (integer-valued) data vector 'z', determine which class it belongs to, by first converting it to a vector of doubles. Return the best class, its name and its relative probability

    z

    the vector to classify

    Definition Classes
    ClassifierRealClassifier
  7. def clearConfusion(): Unit

    Clear the total cummulative confusion matrix.

    Clear the total cummulative confusion matrix.

    Definition Classes
    ConfusionFit
  8. def confusion(yp: VectoI, yy: VectoI = y): MatriI

    Compare the actual class 'y' vector versus the predicted class 'yp' vector, returning the confusion matrix 'cmat', which for 'k = 2' is

    Compare the actual class 'y' vector versus the predicted class 'yp' vector, returning the confusion matrix 'cmat', which for 'k = 2' is

    yp 0 1 ---------- y 0 | tn fp | 1 | fn tp | ----------

    Note: ScalaTion's confusion matrix is Actual × Predicted, but to swap the position of actual 'y' (rows) with predicted 'yp' (columns) simply use 'cmat.t', the transpose of 'cmat'.

    yp

    the precicted class values/labels

    yy

    the actual class values/labels for full (y) or test (y_e) dataset

    Definition Classes
    ConfusionFit
    See also

    www.dataschool.io/simple-guide-to-confusion-matrix-terminology

  9. def contrast(yp: VectoI, yy: VectoI = y): Unit

    Contract the actual class 'yy' vector versus the predicted class 'yp' vector.

    Contract the actual class 'yy' vector versus the predicted class 'yp' vector.

    yp

    the predicted class values/labels

    yy

    the actual class values/labels for full (y) or test (y_e) dataset

    Definition Classes
    ConfusionFit
  10. def corrected_cov(xc: MatriD): MatriD

    Compute the corrected covariance matrix.

    Compute the corrected covariance matrix.

    xc

    the corrected martix whose corrected covariance matrix is sought

  11. def crossValidate(nx: Int = 10, show: Boolean = false): Array[Statistic]

    Test the accuracy of the classified results by cross-validation, returning the Quality of Fit (QoF) measures such as accuracy.

    Test the accuracy of the classified results by cross-validation, returning the Quality of Fit (QoF) measures such as accuracy. This method slices out instances/rows to form the test dataset.

    nx

    number of folds/crosses and cross-validations (defaults to 10x).

    show

    the show flag (show result from each iteration)

    Definition Classes
    ClassifierRealClassifier
  12. def crossValidateRand(nx: Int = 10, show: Boolean = false): Array[Statistic]

    Test the accuracy of the classified results by cross-validation, returning the Quality of Fit (QoF) measures such as accuracy.

    Test the accuracy of the classified results by cross-validation, returning the Quality of Fit (QoF) measures such as accuracy. This method randomizes the instances/rows selected for the test dataset.

    nx

    number of folds/crosses and cross-validations (defaults to 10x).

    show

    the show flag (show result from each iteration)

    Definition Classes
    ClassifierRealClassifier
  13. def diagnose(e: VectoD, yy: VectoD, yp: VectoD, w: VectoD = null, ym: Double = noDouble): Unit

    Diagnose the health of the model by computing the Quality of Fit (QoF) measures, from the error/residual vector and the predicted & actual responses.

    Diagnose the health of the model by computing the Quality of Fit (QoF) measures, from the error/residual vector and the predicted & actual responses. For some models the instances may be weighted.

    e

    the m-dimensional error/residual vector (yy - yp)

    yy

    the actual response vector to use (test/full)

    yp

    the predicted response vector (test/full)

    w

    the weights on the instances (defaults to null)

    ym

    the mean of the actual response vector to use (test/full)

    Definition Classes
    ConfusionFitQoF
    See also

    Regression_WLS

  14. def eval(xx: MatriD, yy: VectoD = null): ClassifierReal

    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.

    xx

    the integer-valued test vectors stored as rows of a matrix

    yy

    the classification vector (impl. classes should ignore or default yy to y)

    Definition Classes
    ClassifierRealModel
  15. def f1_measure(p: Double, r: Double): Double

    Compute the F1-measure, i.e., the harmonic mean of the precision and recall.

    Compute the F1-measure, i.e., the harmonic mean of the precision and recall.

    p

    the precision

    r

    the recall

    Definition Classes
    ConfusionFit
  16. def f1v: VectoD

    Compute the micro-F1-measure vector, i.e., the harmonic mean of the precision and recall.

    Compute the micro-F1-measure vector, i.e., the harmonic mean of the precision and recall.

    Definition Classes
    ConfusionFit
  17. def f_(z: Double): String

    Format a double value.

    Format a double value.

    z

    the double value to format

    Definition Classes
    QoF
  18. 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
    ClassifierReal
  19. def fit: VectoD

    Return the Quality of Fit (QoF) measures corresponding to the labels given above in the 'fitLabel' method.

    Return the Quality of Fit (QoF) measures corresponding to the labels given above in the 'fitLabel' method.

    Definition Classes
    ConfusionFitQoF
  20. def fitLabel: Seq[String]

    Return the labels for the Quality of Fit (QoF) measures.

    Return the labels for the Quality of Fit (QoF) measures. Override to add additional QoF measures.

    Definition Classes
    ConfusionFitQoF
  21. def fitLabel_v: Seq[String]

    Return the labels for the Quality of Fit (QoF) measures.

    Return the labels for the Quality of Fit (QoF) measures. Override to add additional QoF measures.

    Definition Classes
    ConfusionFit
  22. def fitMap: Map[String, String]

    Build a map of quality of fit measures (use of LinkedHashMap makes it ordered).

    Build a map of quality of fit measures (use of LinkedHashMap makes it ordered).

    Definition Classes
    QoF
  23. def fitMicroMap: Map[String, VectoD]

    Return the Quality of Fit (QoF) vector micor-measures, i.e., measures for each class.

    Return the Quality of Fit (QoF) vector micor-measures, i.e., measures for each class.

    Definition Classes
    ConfusionFit
  24. final def flaw(method: String, message: String): Unit
    Definition Classes
    Error
  25. def help: String

    Return the help string that describes the Quality of Fit (QoF) measures provided by the ConfusionFit class.

    Return the help string that describes the Quality of Fit (QoF) measures provided by the ConfusionFit class. Override to correspond to 'fitLabel'.

    Definition Classes
    ConfusionFitQoF
  26. def hparameter: HyperParameter

    Return the model hyper-parameters (if none, return null).

    Return the model hyper-parameters (if none, return null). Hyper-parameters may be used to regularize parameters or tune the optimizer.

    Definition Classes
    ClassifierRealModel
  27. def kappa: Double

    Compute Cohen's 'kappa' coefficient that measures agreement between actual 'y' and predicted 'yp' classifications.

    Compute Cohen's 'kappa' coefficient that measures agreement between actual 'y' and predicted 'yp' classifications.

    Definition Classes
    ConfusionFit
    See also

    en.wikipedia.org/wiki/Cohen%27s_kappa

  28. val modelConcept: URI

    An optional reference to an ontological concept

    An optional reference to an ontological concept

    Definition Classes
    Model
  29. def modelName: String

    An optional name for the model (or modeling technique)

    An optional name for the model (or modeling technique)

    Definition Classes
    Model
  30. def p_r_s(): Unit

    Compute the micro-precision, micro-recall and micro-specificity vectors which have elements for each class i in {0, 1, ...

    Compute the micro-precision, micro-recall and micro-specificity vectors which have elements for each class i in {0, 1, ... k-1}. -------------------------------------------------------------------------- Precision is the fraction classified as true that are actually true. Recall (sensitivity) is the fraction of the actually true that are classified as true. Specificity is the fraction of the actually false that are classified as false. -------------------------------------------------------------------------- Note, for 'k = 2', ordinary precision 'p', recall 'r' and specificity 's' will correspond to the last elements in the 'pv', 'rv' and 'sv' micro vectors.

    Definition Classes
    ConfusionFit
  31. def parameter: VectoD

    Return the vector of model parameter vector.

    Return the vector of model parameter vector.

    Definition Classes
    LDAModel
  32. def pseudo_rSq: Double

    Compute the Efron's pseudo R-squared value.

    Compute the Efron's pseudo R-squared value. Override to McFadden's, etc.

    Definition Classes
    ConfusionFit
  33. def report: String

    Return a basic report on the trained model.

    Return a basic report on the trained model.

    Definition Classes
    ClassifierRealModel
  34. def reset(): Unit

    Reset method not applicable.

    Reset method not applicable.

    Definition Classes
    LDAClassifier
  35. def setStream(str: Int = 0): Unit

    Set the random number 'stream' to 'str'.

    Set the random number 'stream' to 'str'. This is useful for testing purposes, since a fixed stream will follow the same sequence each time.

    str

    the new fixed random number stream

    Definition Classes
    Classifier
  36. def size: Int

    Return the number of data vectors in training/test-set (# rows).

    Return the number of data vectors in training/test-set (# rows).

    Definition Classes
    ClassifierRealClassifier
  37. def summary(b: VectoD = null, show: Boolean = false): String

    Produce a summary report with diagnostics and the overall quality of fit.

    Produce a summary report with diagnostics and the overall quality of fit.

    b

    the parameters of the model

    show

    flag indicating whether to print the summary

    Definition Classes
    ConfusionFit
  38. def test(xx: MatriD, 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 real-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
    ClassifierReal
  39. def test(itest: Ints): 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
    ClassifierRealClassifier
  40. 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
  41. def tn_fp_fn_tp(con: MatriI = cmat): (Double, Double, Double, Double)

    Return the confusion matrix for 'k = 2' as a tuple (tn, fp, fn, tp).

    Return the confusion matrix for 'k = 2' as a tuple (tn, fp, fn, tp).

    con

    the confusion matrix (defaults to cmat)

    Definition Classes
    ConfusionFit
  42. def total_cmat(): MatriI

    Return a copy of the total cummulative confusion matrix 'tcmat' and clear 'tcmat'.

    Return a copy of the total cummulative confusion matrix 'tcmat' and clear 'tcmat'.

    Definition Classes
    ConfusionFit
  43. def train(itest: Ints): LDA

    Train the classifer by computing 'pcovar', 'ipcovar' and 'prior' that are needed to compute the discriminant functions 'f'.

    Train the classifer by computing 'pcovar', 'ipcovar' and 'prior' that are needed to compute the discriminant functions 'f'. These are computed in the 'classify' method.

    itest

    the indices of the test data - FIX - not used yet

    Definition Classes
    LDAClassifier
  44. def train(xx: MatriD = null, yy: VectoD = null): 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.

    xx

    the data/input matrix (impl. classes should ignore or default xx to x)

    yy

    the response/classification vector (impl. classes should ignore or default yy to y)

    Definition Classes
    ClassifierModel
  45. 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
  46. 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). Also may be used for binning into two categories.

    Definition Classes
    ClassifierReal