R/coef.gensvm.R

In gensvm: A Generalized Multiclass Support Vector Machine

#' @title Get the coefficients of the fitted GenSVM model
#'
#' @description Returns the model coefficients of the GenSVM object
#'
#' @param object a \code{gensvm} object
#' @param \dots further arguments are ignored
#'
#' @return The coefficients of the GenSVM model. This is a matrix of size
#' \eqn{(n_{features} + 1) x (n_{classes} - 1)}. This matrix is used to project 
#' the input data to a low dimensional space using the equation: \eqn{XW + t} 
#' where \eqn{X} is the input matrix, \eqn{t} is the first row of the matrix 
#' returned by this function, and \eqn{W} is the \eqn{n_{features} x 
#' (n_{classes} - 1)} matrix formed by the remaining rows.
#'
#' @author
#' Gerrit J.J. van den Burg, Patrick J.F. Groenen \cr
#' Maintainer: Gerrit J.J. van den Burg <gertjanvandenburg@gmail.com>
#'
#' @references
#' Van den Burg, G.J.J. and Groenen, P.J.F. (2016). \emph{GenSVM: A Generalized 
#' Multiclass Support Vector Machine}, Journal of Machine Learning Research, 
#' 17(225):1--42. URL \url{https://jmlr.org/papers/v17/14-526.html}.
#'
#' @seealso
#' \code{\link{gensvm}}, \code{\link{plot.gensvm}}, 
#' \code{\link{predict.gensvm}}, \code{\link{gensvm-package}}
#'
#' @method coef gensvm
#'
#' @export
#'
#' @importFrom stats coef
#'
#' @examples
#' x <- iris[, -5]
#' y <- iris[, 5]
#'
#' fit <- gensvm(x, y)
#' V <- coef(fit)
#'
coef.gensvm <- function(object, ...)
{
    V <- object$V
    x <- eval.parent(object$call$x)
    if (!is.null(colnames(x)) && length(colnames(x)) == dim(V)[1]) {
        name <- c("translation", colnames(x))
        rownames(V) <- name
    }
    return(V)
}