HH (version 2.1-30)

ci.plot: Plot confidence and prediction intervals for simple linear regression

Description

The data, the least squares line, the confidence interval lines, and the prediction interval lines for a simple linear regression (lm(y ~ x)) are displayed. Tick marks are placed at the location of xbar, the x-value of the narrowest interval.

Usage

ci.plot(lm.object, ...)

## S3 method for class 'lm':
ci.plot(lm.object,
        xlim=range(data[, x.name]),
        newdata,
        conf.level=.95,
        data=model.frame(lm.object),
        newfit,
        ylim,
        pch=16,
        main.cex=1,
        main=list(paste(100*conf.level,
          "% confidence and prediction intervals for ",
          substitute(lm.object), sep=""), cex=main.cex), ...
        )

Arguments

lm.object
Linear model for one y and one x variable.
xlim
xlim for plot. Default is based on data from which lm.object was constructed.
newdata
data.frame containing data for which predictions are wanted. The variable name of the column must be identical to the name of the predictor variable in the model object. Defaults to a data.frame containing a vector spanni
conf.level
Confidence level for intervals, defaults to .95
data
data extracted from the lm.object
newfit
Constructed data.frame containing the predictions,confidence interval, and prediction interval for the newdata.
ylim
ylim for plot. Default is based on the constructed prediction interval.
pch
Plotting character for observed points.
main.cex
Font size for main title.
main
Main title for plot
...
Additional arguments to be passed to panel function.

Value

  • "trellis" object containing the plot.

See Also

lm, predict.lm

Examples

Run this code
tmp <- data.frame(x=rnorm(20), y=rnorm(20))
tmp.lm <- lm(y ~ x, data=tmp)
ci.plot(tmp.lm)

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