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authorranke <ranke@5fad18fb-23f0-0310-ab10-e59a3bee62b4>2014-04-24 16:03:41 +0000
committerranke <ranke@5fad18fb-23f0-0310-ab10-e59a3bee62b4>2014-04-24 16:03:41 +0000
commite83723b497d97cfb4e9e3a9803e06c81e7f0b12a (patch)
tree3cde2d89dcba3d6b07ba79b0562d843e1351c7cb /trunk/chemCal/R/lod.R
parent763c3bd1f1c9886bb5747b98c9272d3e26bd514d (diff)
- Added ChangeLog
- Bugfix for lod() for the case of small x values (see ChangeLog) - Version 0.1-32 as just submitted to CRAN - Got rid of trunk directory, as I will not find the time to finish what I started there and it may confuse visitors of viewcvs in kriemhild git-svn-id: http://kriemhild.uft.uni-bremen.de/svn/chemCal@31 5fad18fb-23f0-0310-ab10-e59a3bee62b4
Diffstat (limited to 'trunk/chemCal/R/lod.R')
-rw-r--r--trunk/chemCal/R/lod.R53
1 files changed, 0 insertions, 53 deletions
diff --git a/trunk/chemCal/R/lod.R b/trunk/chemCal/R/lod.R
deleted file mode 100644
index f5bbb7d..0000000
--- a/trunk/chemCal/R/lod.R
+++ /dev/null
@@ -1,53 +0,0 @@
-lod <- function(object, ..., alpha = 0.05, beta = 0.05, method = "default")
-{
- UseMethod("lod")
-}
-
-lod.default <- function(object, ..., alpha = 0.05, beta = 0.05, method = "default")
-{
- stop("lod is only implemented for univariate lm objects.")
-}
-
-lod.lm <- function(object, ..., alpha = 0.05, beta = 0.05, method = "default")
-{
- if (length(object$weights) > 0) {
- stop(paste(
- "\nThe detemination of a lod from calibration models obtained by",
- "weighted linear regression requires confidence intervals for",
- "predicted y values taking into account weights for the x values",
- "from which the predictions are to be generated.",
- "This is not supported by the internally used predict.lm method.",
- sep = "\n"
- ))
- }
- xname <- names(object$model)[[2]]
- yname <- names(object$model)[[1]]
- newdata <- data.frame(0)
- names(newdata) <- xname
- y0 <- predict(object, newdata, interval = "prediction",
- level = 1 - 2 * alpha)
- yc <- y0[[1,"upr"]]
- if (method == "din") {
- y0.d <- predict(object, newdata, interval = "prediction",
- level = 1 - 2 * beta)
- deltay <- y0.d[[1, "upr"]] - y0.d[[1, "fit"]]
- lod.y <- yc + deltay
- lod.x <- inverse.predict(object, lod.y)$Prediction
- } else {
- f <- function(x) {
- newdata <- data.frame(x)
- names(newdata) <- xname
- pi.y <- predict(object, newdata, interval = "prediction",
- level = 1 - 2 * beta)
- yd <- pi.y[[1,"lwr"]]
- (yd - yc)^2
- }
- lod.x <- optimize(f,interval=c(0,max(object$model[[xname]])))$minimum
- newdata <- data.frame(x = lod.x)
- names(newdata) <- xname
- lod.y <- predict(object, newdata)
- }
- lod <- list(lod.x, lod.y)
- names(lod) <- c(xname, yname)
- return(lod)
-}

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