diff options
author | ranke <ranke@5fad18fb-23f0-0310-ab10-e59a3bee62b4> | 2006-06-23 15:33:27 +0000 |
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committer | ranke <ranke@5fad18fb-23f0-0310-ab10-e59a3bee62b4> | 2006-06-23 15:33:27 +0000 |
commit | 9e0dae397df8c18e7333d2604cae96b2a7927420 (patch) | |
tree | b513b791985426bab6c18850d2f8c308c411c1a5 /man/lod.Rd | |
parent | fb7ea47c774f67b8c26a6844f4ade8935a8653cc (diff) |
- inverse.predict now has a var.s argument instead of the never
tested ss argument. This is documented in the updated vignette
- loq() now has w.loq and var.loq arguments, and stops with a message
if neither are specified and the model has weights.
- calplot doesn't stop any more for weighted regression models, but
only refrains from drawing prediction bands
- Added method = "din" to lod(), now that I actually have it (DIN 32645) and
was able to see which approximation is used therein.
- removed the demos, as the examples and tests are already partially
duplicated
- The vignette is more of a collection of various notes, but should
certainly be helpful for the user.
- Version bump to 0.1-xxx
git-svn-id: http://kriemhild.uft.uni-bremen.de/svn/chemCal@16 5fad18fb-23f0-0310-ab10-e59a3bee62b4
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} |