# dfbetaPlots

##### dfbeta and dfbetas Index Plots

These functions display index plots of dfbeta (effect on coefficients of deleting each observation in turn) and dfbetas (effect on coefficients of deleting each observation in turn, standardized by a deleted estimate of the coefficient standard error). In the plot of dfbeta, horizontal lines are drawn at 0 and +/- one standard error; in the plot of dfbetas, horizontal lines are drawn and 0 and +/- 1.

- Keywords
- hplot, regression

##### Usage

`dfbetaPlots(model, ...)`dfbetasPlots(model, ...)

# S3 method for lm
dfbetaPlots(model, terms= ~ ., intercept=FALSE, layout=NULL, ask,
main, xlab, ylab, labels=rownames(dfbeta),
id.method="y",
id.n=if(id.method[1]=="identify") Inf else 0, id.cex=1,
id.col=palette()[1], id.location="lr", col=palette()[1], grid=TRUE, ...)

# S3 method for lm
dfbetasPlots(model, terms=~., intercept=FALSE, layout=NULL, ask,
main, xlab, ylab,
labels=rownames(dfbeta), id.method="y",
id.n=if(id.method[1]=="identify") Inf else 0, id.cex=1,
id.col=palette()[1], id.location="lr", col=palette()[1], grid=TRUE, ...)

##### Arguments

- model
model object produced by

`lm`

or`glm`

.- terms
A one-sided formula that specifies a subset of the terms in the model. One dfbeta or dfbetas plot is drawn for each regressor. The default

`~.`

is to plot against all terms in the model with the exception of an intercept. For example, the specification`terms = ~.-X3`

would plot against all terms except for`X3`

. If this argument is a quoted name of one of the terms, the index plot is drawn for that term only.- intercept
Include the intercept in the plots; default is

`FALSE`

.- layout
If set to a value like

`c(1, 1)`

or`c(4, 3)`

, the layout of the graph will have this many rows and columns. If not set, the program will select an appropriate layout. If the number of graphs exceed nine, you must select the layout yourself, or you will get a maximum of nine per page. If`layout=NA`

, the function does not set the layout and the user can use the`par`

function to control the layout, for example to have plots from two models in the same graphics window.- main
The title of the graph; if missing, one will be supplied.

- xlab
Horizontal axis label; defaults to

`"Index"`

.- ylab
Vertical axis label; defaults to coefficient name.

- ask
If

`TRUE`

, ask the user before drawing the next plot; if`FALSE`

, the default, don't ask.- …
optional additional arguments to be passed to

`plot`

,`points`

, and`showLabels`

- 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.- col
color for points; defaults to the first entry in the color

`palette`

.- grid
If

`TRUE`

, the default, a light-gray background grid is put on the graph

##### Value

`NULL`

. These functions are used for their side effect: producing
plots.

##### References

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.

##### See Also

##### Examples

```
# NOT RUN {
dfbetaPlots(lm(prestige ~ income + education + type, data=Duncan))
dfbetasPlots(glm(partic != "not.work" ~ hincome + children,
data=Womenlf, family=binomial))
# }
```

*Documentation reproduced from package car, version 2.1-6, License: GPL (>= 2)*