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+\name{lod}
+\alias{lod}
+\alias{lod.lm}
+\alias{lod.rlm}
+\alias{lod.default}
+\alias{loq}
+\alias{loq.lm}
+\alias{loq.rlm}
+\alias{loq.default}
+\title{Estimate a limit of detection (LOD) or quantification (LOQ)}
+\usage{
+ lod(object, \dots, alpha = 0.05, k = 1, n = 1, w = "auto")
+ loq(object, \dots, alpha = 0.05, k = 3, n = 1, w = "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.
+ }
+ \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 LOD/LOQ.
+ }
+ \item{n}{
+ The number of replicate measurements for which the LOD/LOQ should be
+ specified.
+ }
+ \item{w}{
+ The weight that should be attributed to the LOD/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.
+ }
+}
+\value{
+ The estimated limit of detection for a model used for calibration.
+}
+\description{
+ A useful operationalisation of a lower limit L of a measurement method is
+ simply the solution of the equation
+ \deqn{L = k c(L)}{L = k * c(L)}
+ where c(L) is half of the lenght of the confidence interval at the limit L.
+}
+\examples{
+ data(din32645)
+ m <- lm(y ~ x, data = din32645)
+ lod(m)
+}
+\keyword{manip}

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