diff options
Diffstat (limited to 'man/lod.Rd')
| -rw-r--r-- | man/lod.Rd | 20 |
1 files changed, 14 insertions, 6 deletions
@@ -5,7 +5,7 @@ \alias{lod.default} \title{Estimate a limit of detection (LOD)} \usage{ - lod(object, \dots, alpha = 0.05, beta = 0.05) + lod(object, \dots, alpha = 0.05, beta = 0.05, method = "default") } \arguments{ \item{object}{ @@ -24,10 +24,18 @@ \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. } + 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 @@ -39,7 +47,7 @@ one-sided significance test). } \note{ - - The default values for alpha and beta are recommended by IUPAC. + - 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). @@ -68,8 +76,8 @@ # The critical value (decision limit, German Nachweisgrenze) can be obtained # by using beta = 0.5: lod(m, alpha = 0.01, beta = 0.5) - # or approximated by - 2 * lod(m, alpha = 0.01, beta = 0.5)$x - # for the case of known, constant variance (homoscedastic data) +} +\seealso{ + Examples for \code{\link{din32645}} } \keyword{manip} |