asbio (version 1.9-2)

partial.resid.plot: Partial residual plots for interpretation of multiple regression.

Description

The function creates partial residual plots which help a user graphically determine the effect of a single predictor with respect to all other predictors in a multiple regression model.

Usage

partial.resid.plot(x, smooth.span = 0.8, lf.col = 2, sm.col = 4,...)

Value

Returns p partial residual plots, where p = the number of explanatory variables.

Arguments

x

A output object of class lm or class glm

smooth.span

Degree of smoothing for smoothing line.

lf.col

Color for linear fit.

sm.col

Color for smoother fit.

...

Additional arguments from plot.

Author

Ken Aho

Details

Creates partial residual plots (see Kutner et al. 2002). Smoother lines from lowess and linear fits from lm are imposed over plots to help an investigator determine the effect of a particular X variable on Y with all other variables in the model. The function automatically inserts explanatory variable names on axes.

References

Kutner, M. H., Nachtsheim, C. J., Neter, J., and W. Li. (2005) Applied Linear Statistical Models, 5th edition. McGraw-Hill, Boston.

See Also

partial.R2

Examples

Soil.C<-c(13,20,10,11,2,25,30,25,23)
Soil.N<-c(1.2,2,1.5,1,0.3,2,3,2.7,2.5)
Slope<-c(15,14,16,12,10,18,25,24,20)
Aspect<-c(45,120,100,56,5,20,5,15,15)
Y<-c(20,30,10,15,5,45,60,55,45)
x <- lm(Y ~ Soil.N + Soil.C + Slope + Aspect)
op <- par(mfrow=c(2,2),mar=c(5,4,1,1.5))
partial.resid.plot(x)
par(op)