R/lqmm_S3_residuals.R

In gforge/lqmm_gforge: Linear Quantile Mixed Models

#' Residuals from an \code{lqmm} Object
#'
#' The residuals at level 0 correspond to population residuals (based only on
#' the fixed effects estimates). The residuals at level 1 are obtained by
#' adding the best linear predictions of the random effects to the predictions
#' at level 0 and the subtracting these from the model response.
#'
#'
#' @param object an \code{lqmm} object.
#' @param level an optional integer vector giving the level of grouping to be
#' used in obtaining the predictions. Level zero corresponds to the population
#' residuals.
#' @param \dots not used.
#' @return a matrix of residuals.
#' @author Marco Geraci
#' @seealso \code{\link{lqmm}}, \code{\link{predict.lqmm}},
#' \code{\link{coef.lqmm}}, \code{\link{ranef.lqmm}},
#' @references Geraci M and Bottai M (2014). Linear quantile mixed models.
#' Statistics and Computing, 24(3), 461--479. doi: 10.1007/s11222-013-9381-9.
#' @keywords residuals
residuals.lqmm <- function(object, level = 0, ...) {
  object$y[object$revOrder] - predict(object, level = level)
}