aboutsummaryrefslogtreecommitdiff
path: root/trunk/man/lod.Rd
diff options
context:
space:
mode:
Diffstat (limited to 'trunk/man/lod.Rd')
-rw-r--r--trunk/man/lod.Rd83
1 files changed, 0 insertions, 83 deletions
diff --git a/trunk/man/lod.Rd b/trunk/man/lod.Rd
deleted file mode 100644
index e468e1d..0000000
--- a/trunk/man/lod.Rd
+++ /dev/null
@@ -1,83 +0,0 @@
-\name{lod}
-\alias{lod}
-\alias{lod.lm}
-\alias{lod.rlm}
-\alias{lod.default}
-\title{Estimate a limit of detection (LOD)}
-\usage{
- lod(object, \dots, alpha = 0.05, beta = 0.05, method = "default")
-}
-\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{\dots}{
- Placeholder for further arguments that might be needed by
- future implementations.
- }
- \item{alpha}{
- The error tolerance for the decision limit (critical value).
- }
- \item{beta}{
- The error tolerance beta for the detection limit.
- }
- \item{method}{
- The default method uses a prediction interval at the LOD
- for the estimation of the LOD, which obviously requires
- iteration. This is described for example in Massart, p. 432 ff.
- The \dQuote{din} method uses the prediction interval at
- x = 0 as an approximation.
- }
-}
-\value{
- A list containig the corresponding x and y values of the estimated limit of
- detection of a model used for calibration.
-}
-\description{
- The decision limit (German: Nachweisgrenze) is defined as the signal or
- analyte concentration that is significantly different from the blank signal
- with a first order error alpha (one-sided significance test).
- The detection limit, or more precise, the minimum detectable value
- (German: Erfassungsgrenze), is then defined as the signal or analyte
- concentration where the probability that the signal is not detected although
- the analyte is present (type II or false negative error), is beta (also a
- one-sided significance test).
-}
-\note{
- - The default values for alpha and beta are the ones recommended by IUPAC.
- - The estimation of the LOD in terms of the analyte amount/concentration
- xD from the LOD in the signal domain SD is done by simply inverting the
- calibration function (i.e. assuming a known calibration function).
- - The calculation of a LOD from weighted calibration models requires
- a weights argument for the internally used \code{\link{predict.lm}}
- function, which is currently not supported in R.
-}
-\references{
- Massart, L.M, Vandenginste, B.G.M., Buydens, L.M.C., De Jong, S., Lewi, P.J.,
- Smeyers-Verbeke, J. (1997) Handbook of Chemometrics and Qualimetrics: Part A,
- Chapter 13.7.8
-
- J. Inczedy, T. Lengyel, and A.M. Ure (2002) International Union of Pure and
- Applied Chemistry Compendium of Analytical Nomenclature: Definitive Rules.
- Web edition.
-
- Currie, L. A. (1997) Nomenclature in evaluation of analytical methods including
- detection and quantification capabilities (IUPAC Recommendations 1995).
- Analytica Chimica Acta 391, 105 - 126.
-}
-\examples{
-data(din32645)
-m <- lm(y ~ x, data = din32645)
-lod(m)
-
-# The critical value (decision limit, German Nachweisgrenze) can be obtained
-# by using beta = 0.5:
-lod(m, alpha = 0.01, beta = 0.5)
-}
-\seealso{
- Examples for \code{\link{din32645}}
-}
-\keyword{manip}

Contact - Imprint