pmoe: Penalized Mixtures of Experts

Description Usage Arguments Value References

Description

Train a penalized mixture of experts model by IPOPT.

Usage

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pmoe(X, ...)

## S3 method for class 'formula'
pmoe(formula, data, subset, na.action, ...)

## Default S3 method:
pmoe(X, y, colsGating = 1:ncol(X),
  colsExperts = 1:ncol(X), interceptGating = TRUE,
  interceptExperts = TRUE, offsetGating = NULL, offsetExperts = NULL,
  J = 2, lambda, alpha = 1, penalty = c("ungrouped", "grouped"),
  type.multinomial = c("ungrouped", "grouped"), model = c("binomial",
  "multinomial"), standardize = FALSE, genetic = FALSE,
  ipopt.max.iter = 500, ipopt.tol = 1e-06, ...)

Arguments

X

(Required if no formula is given as principal argument.) A matrix or data.frame or Matrix containing the explanatory variables (must not contain an intercept column).

formula

A formula with two right-hand sides of the form y ~ expert model | gating model. The normal formula syntax applies (see Formula). In order to use all available columns one or both right-hand sides can be dots (y ~ . | ., y ~ . | gating model). Both right-hand sides normally contain an intercept (which is not penalized) that can be removed by adding 0 or - 1. Offsets are allowed, too. The left-hand side should be a vector indicating the class membership, preferably a factor.

data

A data.frame from which variables specified in formula are to be taken.

subset

A subset...

na.action

...

y

(Required if no formula is given as principal argument.) A factor specifying the class membership for each observation.

colsGating

Names or indices of columns in X to be used for the gating model. Default is all columns.

colsExperts

Names or indices of columns in X to be used for the expert models. Default is all columns.

interceptGating

Logical. Does the gating model include an intercept? If TRUE, an intercept column is added to X. Defaults to TRUE.

interceptExperts

Logical. Does the expert model include an intercept? If TRUE, an intercept column is added to X. Defaults to TRUE.

offsetGating

Offset term for the gating model.

offsetExperts

Offset term for the expert model.

J

The number of experts / mixture components. Defaults to 2.

lambda

Penalty parameter. Can be a scalar or a vector of length 1+J with different components for the gating and the J expert models. All components must be >= 0.

alpha

Mixing parameter for the elastic net penalty. Can be a scalar or a vector of length 1+J with different components for the gating and the J expert models. All components must be in [0,1]. Defaults to 1.

penalty

...

type.multinomial

"grouped", "ungrouped".

model

...

standardize

Logical. Should the columns of X be standardized prior to fitting the model? Defaults to FALSE. If TRUE the coefficients are returned on the original scale.

genetic

Logical.

ipopt.max.iter

The maximum number of IPOPT iterations.

ipopt.tol

Tolerance for IPOPT convergence.

...

Further arguments.

Value

An object of class pmoe.

References

Waechter, A. and Biegler, L. T. (2006), On the Implementation of an Interior-Point Filter Line-Search Algorithm for Large-Scale Nonlinear Programming, Mathematical Programming, 106, 25-57.


schiffner/pmoe documentation built on May 29, 2019, 3:39 p.m.