DAAG: lmdiags – R documentation

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lmdiags

Return data required for diagnostic plots

Description

This extracts the code that provides the major part of the statistical information used by plot.lm, leaving out the code used to provide the graphs

Usage

lmdiags(x, which = c(1L:3L, 5L), cook.levels = c(0.5, 1), hii=NULL)

Arguments

`x`	This must be an object of class `lm` object, or that inherits from an object of class `lm`.
`which`	a subset of the numbers '1:6', indicating the plots for which statistical information is required
`cook.levels`	Levels for contours of `cook.levels`, by default `c(0.5,1)`
`hii`	Diagonal elements for the hat matrix. If not supplied (`hii=NULL`), they will be calculated from the argument `x`.

Details

See plot.lm for additional information.

Value

`yh`	fitted values
`rs`	standardized residuals (for `glm` models standardized deviance residuals)
`yhn0`	As `yh`, but omitting observations with zero weight
`cook`	Cook's statistics
`rsp`	standardized residuals (for `glm` models standardized Pearson residuals)

Note

This function is designed, in the first place, for use in connection with plotSimDiags, used to give simulations of diagnostic plots for lm objects.

Author(s)

John Maindonald, using code that John Maindonald, Martin Maechler and others had contributed to plot.lm

References

See references for plot.lm

Examples

women.lm <- lm(weight ~ height, data=women)
veclist <- lmdiags(x=women.lm)
## Returns the statistics that are required for graphs 1, 2, 3, and 5

DAAG

Data Analysis and Graphics Data and Functions

v1.24

GPL-3

Authors

John H. Maindonald and W. John Braun

Initial release