R/eq.xpose.R

In andrewhooker/xpose4: Diagnostics for Nonlinear Mixed-Effect Models

# Xpose 4
# An R-based population pharmacokinetic/
# pharmacodynamic model building aid for NONMEM.
# Copyright (C) 1998-2004 E. Niclas Jonsson and Mats Karlsson.
# Copyright (C) 2005-2008 Andrew C. Hooker, Justin J. Wilkins, 
# Mats O. Karlsson and E. Niclas Jonsson.
# Copyright (C) 2009-2010 Andrew C. Hooker, Mats O. Karlsson and 
# E. Niclas Jonsson.

# This file is a part of Xpose 4.
# Xpose 4 is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public License
# as published by the Free Software Foundation, either version 3
# of the License, or (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.

# You should have received a copy of the GNU Lesser General Public License
# along with this program.  A copy can be cound in the R installation
# directory under \share\licenses. If not, see http://www.gnu.org/licenses/.

#' @rdname addid

eq.xpose <- function(x, number = 6, overlap = 0.5)
{
	X <- sort(x)
	if(overlap >= 1) {
		m.per.int <- (length(X) + (number - 1) * overlap)/number
		m.over <- overlap
	}
	else {
		m.per.int <- length(X)/(number * (1 - overlap) + overlap)
		m.over <- overlap * m.per.int
	}
	left <- round((0:(number - 1)) * (m.per.int - m.over)) + 1
	right <- round((1:number) * (m.per.int - m.over) + m.over)
	list(lower=X[left], upper=X[right],middle=(X[right]+X[left])/2)
}