coefplot: Coefficient plots for Multivariate Linear Models

In heplots: Visualizing Hypothesis Tests in Multivariate Linear Models

Coefficient plots for Multivariate Linear Models

Description

Displays confidence ellipses for all parameters in an multivariate linear model, for a given pair of variables. As such, it is a generalization of confidenceEllipse.

Usage

coefplot(object, ...)

## S3 method for class 'mlm'
coefplot(
  object,
  variables = 1:2,
  parm = NULL,
  df = NULL,
  level = 0.95,
  intercept = FALSE,
  Scheffe = FALSE,
  bars = TRUE,
  fill = FALSE,
  fill.alpha = 0.2,
  labels = !add,
  label.pos = NULL,
  xlab,
  ylab,
  xlim = NULL,
  ylim = NULL,
  axes = TRUE,
  main = "",
  add = FALSE,
  lwd = 1,
  lty = 1,
  pch = 19,
  col = palette(),
  cex = 2,
  cex.label = 1.5,
  lty.zero = 3,
  col.zero = 1,
  pch.zero = "+",
  verbose = FALSE,
  ...
)

Arguments

object	A multivariate linear model, such as fit by lm(cbind(y1, y2, ...) ~ ...)
...	Other parameters passed to methods
variables	Response variables to plot, given as their indices or names
parm	Parameters to plot, given as their indices or names
df	Degrees of freedom for hypothesis tests
level	Confidence level for the confidence ellipses
intercept	logical. Include the intercept?
Scheffe	If TRUE, confidence intervals for all parameters have Scheffe coverage, otherwise, individual coverage.
bars	Draw univariate confidence intervals for each of the variables?
fill	a logical value or vector. TRUE means the confidence ellipses will be filled.
fill.alpha	Opacity of the confidence ellipses
labels	Labels for the confidence ellipses
label.pos	Positions of the labels for each ellipse. See label.ellipse
xlab, ylab	x, y axis labels
xlim, ylim	Axis limits
axes	Draw axes?
main	Plot title
add	logical. Add to an existing plot?
lwd	Line widths
lty	Line types
pch	Point symbols for the parameter estimates
col	Colors for the confidence ellipses, points, lines
cex	Character size for points showing parameter estimates
cex.label	Character size for ellipse labels
lty.zero, col.zero, pch.zero	Line type, color and point symbol for horizontal and vertical lines at 0, 0.
verbose	logical. Print parameter estimates and variance-covariance for each parameter?

Value

Returns invisibly a list of the coordinates of the ellipses drawn

Author(s)

Michael Friendly

See Also

confidenceEllipse,

Examples

rohwer.mlm <- lm(cbind(SAT,PPVT,Raven)~n+s+ns, data=Rohwer)

coefplot(rohwer.mlm, lwd=2, 
         main="Bivariate coefficient plot for SAT and PPVT", fill=TRUE)
coefplot(rohwer.mlm, add=TRUE, Scheffe=TRUE, fill=TRUE)

coefplot(rohwer.mlm, var=c(1,3))

mod1 <- lm(cbind(SAT,PPVT,Raven)~n+s+ns+na+ss, data=Rohwer)
coefplot(mod1, lwd=2, fill=TRUE, parm=(1:5),
	main="Bivariate 68% coefficient plot for SAT and PPVT", level=0.68)

heplots documentation built on May 29, 2024, 9:24 a.m.