plot.bootstrap {equate}

Plotting Bootstrap Equating Results

Description

This function plots bootstrap equating results for objects of class “bootstrap”.

Usage

## S3 method for class 'bootstrap'
plot(
  x,
  add = FALSE,
  out = "mean",
  xpoints,
  ypoints,
  addident = TRUE,
  identy,
  identcol = 1,
  rescale = c(0, 1),
  xlab = "Total Score",
  ylab,
  col = rainbow(length(x$args)),
  pch,
  lty = 1,
  subset,
  morepars = NULL,
  addlegend = TRUE,
  legendtext,
  legendplace = "bottomright",
  ...
)

Arguments

x

output from the bootstrap function.

add

logical, with default FALSE, specifying whether to create a new plot or add to the current one.

out

character vector specifying the output to be plotted, either the mean equated scores ("mean"), standard errors ("se"), bias ("bias"), or RMSE ("rmse").

xpoints, ypoints

optional vectors of the same length containing raw scores on forms X and Y, assuming a single group or equivalent groups design.

addident

logical, with default TRUE, for plotting the identity function. The result depends on out.

identy

vector of y coordinates for plotting the identity line. Defaults to the identity function when out = "eqs", otherwise, a horizontal line with intercept 0.

identcol

color used for plotting the identity line.

rescale

intercept and slope, with default 0 and 1, used to rescale all lines before plotting.

xlab, ylab, col, pch, lty

graphical parameters passed to par, with the lengths of col and lty recycled as necessary.

subset

vector for subsetting the output when multiple equating functions are included in x.

morepars

list of additional graphical parameters, excluding xlab, ylab, col, pch, lty.

addlegend

logical, with default TRUE, indicating whether or not a legend should be added.

legendtext

character vector of text to be passed to the legend argument of the legend function, defaulting to a combination of the equating types and methods specified in each equating object.

legendplace

placement of the legend.

...

further arguments passed to or from other methods, excluding graphical parameters.

Details

Lines are plotted for the chosen output type, whether mean equated scores across replications (out = "mean"), standard errors (out = "se"), bias (out = "bias") or RMSE (out = "rmse"). The result is similar to that of plot.equate.

Author(s)

Anthony Albano [e-mail]

See Also

bootstrap, plot.equate

Examples

set.seed(122713)
neat.x <- freqtab(KBneat$x, scales = list(0:36, 0:12))
neat.y <- freqtab(KBneat$y, scales = list(0:36, 0:12))
eqargs <- list(m.t = list(type = "mean", method = "t"),
  l.t = list(type = "lin", method = "t"),
	c.t = list(type = "circ", method = "t"))
bootout <- bootstrap(x = neat.x, y = neat.y, args = eqargs,
	reps = 20)
plot(bootout, out = "se", legendplace = "top")