| % File src/library/stats/man/predict.nls.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2007 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{predict.nls} |
| \title{Predicting from Nonlinear Least Squares Fits} |
| \alias{predict.nls} |
| \usage{ |
| \method{predict}{nls}(object, newdata , se.fit = FALSE, scale = NULL, df = Inf, |
| interval = c("none", "confidence", "prediction"), |
| level = 0.95, \dots) |
| } |
| \description{ |
| \code{predict.nls} produces predicted values, obtained by evaluating |
| the regression function in the frame \code{newdata}. If the logical |
| \code{se.fit} is \code{TRUE}, standard errors of the predictions are |
| calculated. If the numeric argument \code{scale} is set (with |
| optional \code{df}), it is used as the residual standard deviation in |
| the computation of the standard errors, otherwise this is extracted |
| from the model fit. Setting \code{intervals} specifies computation of |
| confidence or prediction (tolerance) intervals at the specified |
| \code{level}. |
| |
| At present \code{se.fit} and \code{interval} are ignored. |
| } |
| \arguments{ |
| \item{object}{An object that inherits from class \code{nls}.} |
| \item{newdata}{A named list or data frame in which to look for variables with |
| which to predict. If \code{newdata} is |
| missing the fitted values at the original data points are returned.} |
| \item{se.fit}{A logical value indicating if the standard errors of the |
| predictions should be calculated. Defaults to \code{FALSE}. At |
| present this argument is ignored.} |
| \item{scale}{A numeric scalar. If it is set (with optional |
| \code{df}), it is used as the residual standard deviation in the |
| computation of the standard errors, otherwise this information is |
| extracted from the model fit. At present this argument is ignored.} |
| \item{df}{A positive numeric scalar giving the number of degrees of |
| freedom for the \code{scale} estimate. At present this argument is |
| ignored.} |
| \item{interval}{A character string indicating if prediction intervals |
| or a confidence interval on the mean responses are to be |
| calculated. At present this argument is ignored.} |
| \item{level}{A numeric scalar between 0 and 1 giving the confidence |
| level for the intervals (if any) to be calculated. At present |
| this argument is ignored.} |
| \item{\dots}{Additional optional arguments. At present no optional |
| arguments are used.} |
| } |
| \value{ |
| \code{predict.nls} produces a vector of predictions. |
| When implemented, \code{interval} will produce a matrix of |
| predictions and bounds with column names \code{fit}, \code{lwr}, and |
| \code{upr}. When implemented, if \code{se.fit} is |
| \code{TRUE}, a list with the following components will be returned: |
| |
| \item{fit}{vector or matrix as above} |
| \item{se.fit}{standard error of predictions} |
| \item{residual.scale}{residual standard deviations} |
| \item{df}{degrees of freedom for residual} |
| } |
| \seealso{ |
| The model fitting function \code{\link{nls}}, |
| \code{\link{predict}}. |
| } |
| \note{ |
| Variables are first looked for in \code{newdata} and then searched for |
| in the usual way (which will include the environment of the formula |
| used in the fit). A warning will be given if the |
| variables found are not of the same length as those in \code{newdata} |
| if it was supplied. |
| } |
| \examples{ |
| \dontshow{od <- options(digits = 5)} |
| require(graphics) |
| |
| fm <- nls(demand ~ SSasympOrig(Time, A, lrc), data = BOD) |
| predict(fm) # fitted values at observed times |
| ## Form data plot and smooth line for the predictions |
| opar <- par(las = 1) |
| plot(demand ~ Time, data = BOD, col = 4, |
| main = "BOD data and fitted first-order curve", |
| xlim = c(0,7), ylim = c(0, 20) ) |
| tt <- seq(0, 8, length = 101) |
| lines(tt, predict(fm, list(Time = tt))) |
| par(opar) |
| \dontshow{options(od)} |
| } |
| \keyword{nonlinear} |
| \keyword{regression} |
| \keyword{models} |