#' Bickel-Doksum transformation for linear mixed models
#'
#' The function transforms the dependent variable of a linear mixed model with
#' one random intercept using the Bickel-Doksum transformation. The
#' transformation parameter can either be estimated using different estimation
#' methods or given.
#'
#' @param object an object of type lme.
#' @param lambda either a character named "estim" if the optimal transformation
#' parameter should be estimated or a numeric value determining a given
#' transformation parameter. Defaults to "estim".
#' @param method a character string. Different estimation methods can be used
#' for the estimation of the optimal transformation parameter:
#' (i) Restricted maximum likelihood approach ("reml"),
#' (ii) Skewness minimization ("skew") and pooled skewness minimization ("pskew"),
#' (iii) Divergence minimization by Kolmogorov-Smirnoff ("div.ks"),
#' by Cramer-von-Mises ("div.cm") or by Kullback-Leibler ("div.kl").
#' @param lambdarange a numeric vector with two elements defining an interval
#' that is used for the estimation of the optimal transformation parameter.
#' Defaults to \code{c(1e-11, 2)}.
#' @param plotit logical. If TRUE, a plot that illustrates the optimal
#' transformation parameter or the given transformation parameter is returned.
#' @param ... other parameters that can be passed to the function.
#' @return an object of class \code{trafo}.
#' @references
#' Battese, G.E., Harter, R.M. and Fuller, W.A. (1988). An Error-Components
#' Model for Predictions of County Crop Areas Using Survey and Satellite Data.
#' Journal of the American Statistical Association, Vol.83, No. 401, 28-36. \cr \cr
#' Gonzalez-Manteiga, W. et al. (2008). Bootstrap mean squared error of
#' a small-area EBLUP. Journal of Statistical Computation and Simulation,
#' 78:5, 443-462.
#' @examples
#' # Load data
#' data("eusilcA_Vienna")
#'
#' # Fit linear mixed model
#' require(nlme)
#' lme_Vienna <- lme(eqIncome ~ eqsize + gender + cash + unempl_ben + age_ben +
#' rent + cap_inv + tax_adj + dis_ben + sick_ben + surv_ben + fam_allow +
#' house_allow, random = ~ 1 | county, data = eusilcA_Vienna,
#' na.action = na.omit)
#'
#' # Transform dependent variable using restricted maximum likelihood
#' bickeldoksum(object = lme_Vienna, lambda = "estim", method = "reml",
#' plotit = FALSE)
#' @export
bickeldoksum_lme <- function(object, lambda = "estim", method = "reml",
lambdarange = c(1e-11, 2), plotit = TRUE, ...) {
trafo <- "bickeldoksum"
oneparam(object = object, trafo = trafo, lambda = lambda, method = method,
lambdarange = lambdarange, plotit = plotit)
# # Get model variables: dependent variable y and explanatory variables x
# formula <- formula(object)
# rand_eff <- names(object$coefficients$random)
# data <- object$data
# x <- model.matrix(formula, data = object$data)
# y <- as.matrix(object$data[paste(formula[2])])
#
#
# # For saving returns
# ans <- list()
#
# # Get the optimal transformation parameter
# if (lambda == "estim") {
# optim <- est_lme(y = y, x = x, formula = formula, data = data,
# rand_eff = rand_eff, method = method,
# lambdarange = lambdarange, trafo = trafo)
#
# lambdaoptim <- optim$lambdaoptim
# measoptim <- optim$measoptim
#
# } else if (is.numeric(lambda)) {
# lambdaoptim <- lambda
# measoptim <- estim_lme(lambda = lambda, y = y, formula = formula,
# data = data, rand_eff = rand_eff, method = method,
# trafo = trafo)
# }
#
# # Plot the curve of the measure with line at the optimal transformation
# # parameter
# if (plotit == TRUE) {
# plot_meas <- plot_trafolme(lambdarange = lambdarange, lambdaoptim = lambdaoptim,
# measoptim = measoptim, y = y, formula = formula,
# data = data, rand_eff = rand_eff, trafo = trafo,
# method = method)
#
# if (!is.character(plot_meas)) {
# # Get plot measures
# ans$lambdavector <- plot_meas$lambdavector
# ans$measvector <- plot_meas$measvector
# } else {
# ans$lambdavector <- NULL
# ans$measvector <- NULL
# }
# } else if (plotit == FALSE) {
# ans$lambdavector <- NULL
# ans$measvector <- NULL
# }
#
#
# # Get vector of transformed and standardized transformed variable
# #ans$yt <- Bick_dok(y = y, lambda = lambdaoptim)
# #ans$zt <- Bick_dok_std(y = y, lambda = lambdaoptim)
#
# # Save transformation family and method
# #ans$family <- "Bickel-Doksum"
#
# ans <- get_transformed(trafo = trafo, ans = ans, y = y, lambda = lambdaoptim)
#
# # Save estimation method
# ans$method <- method
#
# ans$lambdahat <- lambdaoptim
# ans$measoptim <- measoptim
#
# # Get transformed model
# ans$modelt <- get_modelt(object = object, trans_mod = ans, std = FALSE)
#
# # New class trafo
# class(ans) <- "trafo"
# ans
}
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