Uses of Package

Packages that use weka.classifiers.functions
  • Class
    Class for building and using a multinomial logistic regression model with a ridge estimator.

    There are some modifications, however, compared to the paper of leCessie and van Houwelingen(1992):

    If there are k classes for n instances with m attributes, the parameter matrix B to be calculated will be an m*(k-1) matrix.

    The probability for class j with the exception of the last class is

    Pj(Xi) = exp(XiBj)/((sum[j=1..(k-1)]exp(Xi*Bj))+1)

    The last class has probability

    = 1/((sum[j=1..(k-1)]exp(Xi*Bj))+1)

    The (negative) multinomial log-likelihood is thus:

    L = -sum[i=1..n]{
    sum[j=1..(k-1)](Yij * ln(Pj(Xi)))
    +(1 - (sum[j=1..(k-1)]Yij))
    * ln(1 - sum[j=1..(k-1)]Pj(Xi))
    } + ridge * (B^2)

    In order to find the matrix B for which L is minimised, a Quasi-Newton Method is used to search for the optimized values of the m*(k-1) variables.
    Implements stochastic gradient descent for learning various linear models (binary class SVM, binary class logistic regression, squared loss, Huber loss and epsilon-insensitive loss linear regression).
    Implements stochastic gradient descent for learning a linear binary class SVM or binary class logistic regression on text data.
  • Class
    SMOreg implements the support vector machine for regression.