From e83723b497d97cfb4e9e3a9803e06c81e7f0b12a Mon Sep 17 00:00:00 2001 From: ranke Date: Thu, 24 Apr 2014 16:03:41 +0000 Subject: - Added ChangeLog - Bugfix for lod() for the case of small x values (see ChangeLog) - Version 0.1-32 as just submitted to CRAN - Got rid of trunk directory, as I will not find the time to finish what I started there and it may confuse visitors of viewcvs in kriemhild git-svn-id: http://kriemhild.uft.uni-bremen.de/svn/chemCal@31 5fad18fb-23f0-0310-ab10-e59a3bee62b4 --- trunk/chemCal/man/loq.Rd | 77 ------------------------------------------------ 1 file changed, 77 deletions(-) delete mode 100644 trunk/chemCal/man/loq.Rd (limited to 'trunk/chemCal/man/loq.Rd') diff --git a/trunk/chemCal/man/loq.Rd b/trunk/chemCal/man/loq.Rd deleted file mode 100644 index 7541e77..0000000 --- a/trunk/chemCal/man/loq.Rd +++ /dev/null @@ -1,77 +0,0 @@ -\name{loq} -\alias{loq} -\alias{loq.lm} -\alias{loq.rlm} -\alias{loq.default} -\title{Estimate a limit of quantification (LOQ)} -\usage{ - loq(object, \dots, alpha = 0.05, k = 3, n = 1, w.loq = "auto", - var.loq = "auto") -} -\arguments{ - \item{object}{ - A univariate model object of class \code{\link{lm}} or - \code{\link[MASS:rlm]{rlm}} - with model formula \code{y ~ x} or \code{y ~ x - 1}, - optionally from a weighted regression. If weights are specified - in the model, either \code{w.loq} or \code{var.loq} have to - be specified. - } - \item{alpha}{ - The error tolerance for the prediction of x values in the calculation. - } - \item{\dots}{ - Placeholder for further arguments that might be needed by - future implementations. - } - \item{k}{ - The inverse of the maximum relative error tolerated at the - desired LOQ. - } - \item{n}{ - The number of replicate measurements for which the LOQ should be - specified. - } - \item{w.loq}{ - The weight that should be attributed to the LOQ. Defaults - to one for unweighted regression, and to the mean of the weights - for weighted regression. See \code{\link{massart97ex3}} for - an example how to take advantage of knowledge about the - variance function. - } - \item{var.loq}{ - The approximate variance at the LOQ. The default value is - calculated from the model. - } -} -\value{ - The estimated limit of quantification for a model used for calibration. -} -\description{ - The limit of quantification is the x value, where the relative error - of the quantification given the calibration model reaches a prespecified - value 1/k. Thus, it is the solution of the equation - \deqn{L = k c(L)}{L = k * c(L)} - where c(L) is half of the length of the confidence interval at the limit L - (DIN 32645, equivalent to ISO 11843). c(L) is internally estimated by - \code{\link{inverse.predict}}, and L is obtained by iteration. -} -\note{ - - IUPAC recommends to base the LOQ on the standard deviation of the signal - where x = 0. - - The calculation of a LOQ based on weighted regression is non-standard - and therefore not tested. Feedback is welcome. -} -\examples{ -data(massart97ex3) -attach(massart97ex3) -m <- lm(y ~ x) -loq(m) - -# We can get better by using replicate measurements -loq(m, n = 3) -} -\seealso{ - Examples for \code{\link{din32645}} -} -\keyword{manip} -- cgit v1.2.1