HH (version 3.1-8)

resid.squares: plot squared residuals in inches to match the y-dimension

Description

plot squared residuals in inches to match the y-dimension

Usage

resid.squares(x, y, y.hat, resid.plot = "square", ...)

Arguments

x

x values

y

observed y values

y.hat

predicted y values

resid.plot

If "square", then plot the squared residuals. If TRUE (or anything else), then plot straight lines for the residuals.

...

Other graphics arguments.

Details

The goal is to get real squares on the screen or paper. The trick is to play games with the aspect ratio. We find the number of inches that each vertical residual occupies. We then find the number of x-units that corresponds to, and plot a rectangle with height=height in the y-data units and with width=the number of x-units that we just calculated.

References

Heiberger, Richard M. and Holland, Burt (2004b). Statistical Analysis and Data Display: An Intermediate Course with Examples in S-Plus, R, and SAS. Springer Texts in Statistics. Springer. ISBN 0-387-40270-5.

See Also

regr1.plot

Examples

data(hardness)

hardness.lin.lm  <- lm(hardness ~ density, data=hardness)

plot(hardness ~ density, data=hardness, xlim=c(22,73), ylim=c(0,3400))
abline(hardness.lin.lm)
resid.squares(hardness$density, hardness$hardness,
              predict(hardness.lin.lm))

plot(hardness ~ density, data=hardness, xlim=c(22,73), ylim=c(0,3400))
abline(hardness.lin.lm)
resid.squares(hardness$density, hardness$hardness,
              predict(hardness.lin.lm), resid.plot = "line")