S3 Method to plot objects of class monotonicity.class.
Graphic display of the checks of monotonicity.
One graph for each item plotting the estimated item step response functions.
Usage
## S3 method for class 'monotonicity.class':
plot(x, items = all, ask = TRUE, ...)
vector containing the numbers of the items for which the results are depicted graphically.
Default the results for all items are depicted.
ask
Boolean. If TRUE (default), then par("ask"=TRUE); i.e., a hard return between subsequent plots is required.
If FALSE, then par("ask"=FALSE).
...
Optional graphical parameters will be ignored
Value
Returns a graph.
Details
The default graphic device in R may only display the last graph.
References
Molenaar, I.W. and Sijtsma, K. (2000)
User's Manual MSP5 for Windows [Software manual].
Groningen, The Netherlands: IEC ProGAMMA.
Sijtsma, K, and Molenaar, I. W. (2002)
Introduction to nonparametric item response theory.
Thousand Oaks, CA: Sage.
Van der Ark, L. A. (2007).
Mokken scale analysis in R.
Journal of Statistical Software.
http://www.jstatsoft.org