diff options
author | Johannes Ranke <jranke@uni-bremen.de> | 2022-03-31 19:21:03 +0200 |
---|---|---|
committer | Johannes Ranke <jranke@uni-bremen.de> | 2022-03-31 19:59:10 +0200 |
commit | 08465d77a6ca5a9656ac86047c6008f1e7f3e9c7 (patch) | |
tree | f27a775e146748881eb6526ed57298f4bdc40c2f /man/inverse.predict.Rd | |
parent | f4fcef8228ebd5a1a73bc6edc47b5efa259c2e20 (diff) |
Fix URLs in README, convert to roxygenv0.2.3
- The roxygen conversion was done using Rd2roxygen
- Also edit _pkgdown.yml to group the reference
- Use markdown bullet lists for lod and loq docs
Diffstat (limited to 'man/inverse.predict.Rd')
-rw-r--r-- | man/inverse.predict.Rd | 108 |
1 files changed, 59 insertions, 49 deletions
diff --git a/man/inverse.predict.Rd b/man/inverse.predict.Rd index 373623e..08c24d7 100644 --- a/man/inverse.predict.Rd +++ b/man/inverse.predict.Rd @@ -1,67 +1,72 @@ +% Generated by roxygen2: do not edit by hand +% Please edit documentation in R/inverse.predict.lm.R \name{inverse.predict} \alias{inverse.predict} \alias{inverse.predict.lm} \alias{inverse.predict.rlm} \alias{inverse.predict.default} \title{Predict x from y for a linear calibration} -\usage{inverse.predict(object, newdata, \dots, - ws, alpha=0.05, var.s = "auto") +\usage{ +inverse.predict( + object, + newdata, + ..., + ws = "auto", + alpha = 0.05, + var.s = "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}. - } - \item{newdata}{ - A vector of observed y values for one sample. - } - \item{\dots}{ - Placeholder for further arguments that might be needed by - future implementations. - } - \item{ws}{ - The weight attributed to the sample. This argument is obligatory - if \code{object} has weights. - } - \item{alpha}{ - The error tolerance level for the confidence interval to be reported. - } - \item{var.s}{ - The estimated variance of the sample measurements. The default is to take - the residual standard error from the calibration and to adjust it - using \code{ws}, if applicable. This means that \code{var.s} - overrides \code{ws}. - } +\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}.} + +\item{newdata}{A vector of observed y values for one sample.} + +\item{\dots}{Placeholder for further arguments that might be needed by +future implementations.} + +\item{ws}{The weight attributed to the sample. This argument is obligatory +if \code{object} has weights.} + +\item{alpha}{The error tolerance level for the confidence interval to be +reported.} + +\item{var.s}{The estimated variance of the sample measurements. The default +is to take the residual standard error from the calibration and to adjust it +using \code{ws}, if applicable. This means that \code{var.s} overrides +\code{ws}.} } \value{ - A list containing the predicted x value, its standard error and a - confidence interval. +A list containing the predicted x value, its standard error and a +confidence interval. } \description{ - This function predicts x values using a univariate linear model that has been - generated for the purpose of calibrating a measurement method. Prediction - intervals are given at the specified confidence level. - The calculation method was taken from Massart et al. (1997). In particular, - Equations 8.26 and 8.28 were combined in order to yield a general treatment - of inverse prediction for univariate linear models, taking into account - weights that have been used to create the linear model, and at the same - time providing the possibility to specify a precision in sample measurements - differing from the precision in standard samples used for the calibration. - This is elaborated in the package vignette. +This function predicts x values using a univariate linear model that has +been generated for the purpose of calibrating a measurement method. +Prediction intervals are given at the specified confidence level. The +calculation method was taken from Massart et al. (1997). In particular, +Equations 8.26 and 8.28 were combined in order to yield a general treatment +of inverse prediction for univariate linear models, taking into account +weights that have been used to create the linear model, and at the same time +providing the possibility to specify a precision in sample measurements +differing from the precision in standard samples used for the calibration. +This is elaborated in the package vignette. +} +\details{ +This is an implementation of Equation (8.28) in the Handbook of Chemometrics +and Qualimetrics, Part A, Massart et al (1997), page 200, validated with +Example 8 on the same page, extended as specified in the package vignette } \note{ - The function was validated with examples 7 and 8 from Massart et al. (1997). - Note that the behaviour of inverse.predict changed with chemCal version - 0.2.1. Confidence intervals for x values obtained from calibrations with - replicate measurements did not take the variation about the means into account. - Please refer to the vignette for details.} -\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, - p. 200 +The function was validated with examples 7 and 8 from Massart et al. +(1997). Note that the behaviour of inverse.predict changed with chemCal +version 0.2.1. Confidence intervals for x values obtained from calibrations +with replicate measurements did not take the variation about the means into +account. Please refer to the vignette for details. } \examples{ + # This is example 7 from Chapter 8 in Massart et al. (1997) m <- lm(y ~ x, data = massart97ex1) inverse.predict(m, 15) # 6.1 +- 4.9 @@ -84,5 +89,10 @@ m3.means <- lm(y ~ x, w = weights, data = massart97ex3.means) inverse.predict(m3.means, 15, ws = 1.67) # 5.9 +- 2.5 inverse.predict(m3.means, 90, ws = 0.145) # 44.1 +- 7.9 + +} +\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, p. 200 } -\keyword{manip} |