plot.Bwiqid {wiqid}

Plot method for objects of class 'Bwiqid'

Description

Method to display a plot showing the posterior probability distribution of one of the parameters of interest.

Usage

## S3 method for class 'Bwiqid'
plot(x, which=NULL, credMass=0.95,
           ROPE=NULL, compVal=NULL, showCurve=FALSE,
           showMode=FALSE, shadeHDI=NULL,  ...)

Arguments

x

an object of class Bwiqid.

which

character: indicates which parameter to plot. If NULL and x has a defaultPlot attribute, that parameter is plotted; otherwise the parameter in column 1 is plotted.

credMass

the probability mass to include in credible intervals; NULL suppresses plotting.

ROPE

a two element vector, such as c(-1, 1), specifying the limit of the ROPE on the estimate; see Details.

compVal

a value for comparison with the parameter.

showCurve

logical: if TRUE, the posterior density will be represented by a kernel density function instead of a histogram.

showMode

logical: if TRUE, the mode of the posterior density will be shown instead of the mean.

shadeHDI

specifies a colour to shade the area under the curve corresponding to the HDI; NULL for no shading. Ignored if showCurve = FALSE. Usecolours() to see a list of possible colours.

...

other graphical parameters.

Details

The posterior distribution is shown as a histogram or density curve (if showCurve = TRUE), together with the Highest Density Interval. A ROPE and comparison value are also shown if appropriate.

The probability that a parameter precisely zero (or has any other point value) is zero. More interesting is the probability that the difference from zero may be too small to matter. We can define a region of practical equivalence (ROPE) around zero, and obtain the posterior probability that the true value lies therein.

Value

Returns an object of class histogram invisibly. Used mainly for the side effect.

Author(s)

Mike Meredith, adapted from code by John Kruschke.

References

Kruschke, J. K. 2013. Bayesian estimation supersedes the t test. Journal of Experimental Psychology: General 142(2):573-603. doi: 10.1037/a0029146

See Also

postPlot.

Examples

# See examples in dippers.