diff options
Diffstat (limited to 'R/lod.R')
| -rw-r--r-- | R/lod.R | 40 |
1 files changed, 23 insertions, 17 deletions
@@ -1,14 +1,14 @@ -lod <- function(object, ..., alpha = 0.05, beta = 0.05) +lod <- function(object, ..., alpha = 0.05, beta = 0.05, method = "default") { UseMethod("lod") } -lod.default <- function(object, ..., alpha = 0.05, beta = 0.05) +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) +lod.lm <- function(object, ..., alpha = 0.05, beta = 0.05, method = "default") { if (length(object$weights) > 0) { stop(paste( @@ -24,23 +24,29 @@ lod.lm <- function(object, ..., alpha = 0.05, beta = 0.05) yname <- names(object$model)[[1]] newdata <- data.frame(0) names(newdata) <- xname - y0 <- predict(object, newdata, interval="prediction", - level = 1 - 2 * alpha ) + y0 <- predict(object, newdata, interval = "prediction", + level = 1 - 2 * alpha) yc <- y0[[1,"upr"]] - xc <- inverse.predict(object,yc)[["Prediction"]] - f <- function(x) - { - newdata <- data.frame(x) - names(newdata) <- xname - pi.y <- predict(object, newdata, interval = "prediction", + if (method == "din") { + y0.d <- predict(object, newdata, interval = "prediction", level = 1 - 2 * beta) - yd <- pi.y[[1,"lwr"]] - (yd - yc)^2 + 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]])))$minimum + newdata <- data.frame(x = lod.x) + names(newdata) <- xname + lod.y <- predict(object, newdata) } - lod.x <- optimize(f,interval=c(0,max(object$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) |