infIndexPlot {car} | R Documentation

## Influence Index Plot

### Description

Provides index plots of Cook's distances, leverages, Studentized residuals, and outlier significance levels for a regression object.

### Usage

    infIndexPlot(model, ...)

    influenceIndexPlot(model, ...)

    ## S3 method for class 'lm'
    infIndexPlot(model,
         vars=c("Cook", "Studentized", "Bonf", "hat"),
         main="Diagnostic Plots",
         labels, id.method = "y",
         id.n = if(id.method[1]=="identify") Inf else 0,
         id.cex=1, id.col=palette()[1], id.location="lr", grid=TRUE, ...)

### Arguments

`model` | A regression object of class `lm` or `glm`.
`vars` | All the quantities listed in this argument are plotted. Use `"Cook"` for Cook's distances, `"Studentized"` for Studentized residuals, `"Bonf"` for Bonferroni p-values for an outlier test, and and `"hat"` for hat-values (or leverages). Capitalization is optional. All may be abbreviated by the first one or more letters.
`main` | main title for graph
`id.method,labels,id.n,id.cex,id.col,id.location` | Arguments for the labelling of points. The default is `id.n=0` for labeling no points. See `showLabels` for details of these arguments.
`grid` | If TRUE, the default, a light-gray background grid is put on the graph
`...` | Arguments passed to `plot`

### Value

Used for its side effect of producing a graph. Produces four index plots of Cook's distance, Studentized Residuals, the corresponding Bonferroni p-values for outlier tests, and leverages.

### Author(s)

Sanford Weisberg, sandy@umn.edu

### References

Cook, R. D. and Weisberg, S. (1999) Applied Regression, Including Computing and Graphics. Wiley.

Fox, J. (2008) Applied Regression Analysis and Generalized Linear Models, Second Edition. Sage.

Fox, J. and Weisberg, S. (2011) An R Companion to Applied Regression, Second Edition, Sage.

Weisberg, S. (2014) Applied Linear Regression, Fourth Edition, Wiley.

### See Also

`cooks.distance`, `rstudent`, `outlierTest`, `hatvalues`

### Examples

    m1 <- lm(prestige ~ income + education + type, Duncan)
    influenceIndexPlot(m1)

[Package car version 2.1-6 Index]