dfbetaPlots {car} | R Documentation |
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.
dfbetaPlots(model, ...) dfbetasPlots(model, ...) ## S3 method for class '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], col=palette()[1], grid=TRUE, ...) ## S3 method for class '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], col=palette()[1], grid=TRUE, ...)
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. |
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 |
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 |
NULL
. These functions are used for their side effect: producing
plots.
John Fox jfox@mcmaster.ca, Sanford Weisberg sandy@umn.edu
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.
dfbetaPlots(lm(prestige ~ income + education + type, data=Duncan)) dfbetasPlots(glm(partic != "not.work" ~ hincome + children, data=Womenlf, family=binomial))