S3 Method to plot objects of class pmatrix.class.
Graphic display of the checks of pmatrix.
One graph for each item plotting the rows of the P(++) matrix and rows of the P(--) matrix.
If nonintersection holds the lines in the plots of the P(++) matrix must be nondecreasing
and the lines in the plots of the P(--) matrix nust be nonincreasing.
# S3 method for pmatrix.class
plot(x, items = all.items, pmatrix = "both", ci = TRUE,
alpha = .05, color = "black", transparancy = 20, ask = TRUE, ...)Object of class pmatrix.class produced by check.pmatrix.
vector containing the numbers of the item pairs for which the results are depicted graphically. Default the results for all items are depicted.
Valid options are "ppp", "pmm", and "both".
If pmatrix="ppp", then the P(++) matrix is plotted,
if pmatrix="pmm", then the P(--) matrix is plotted,
if pmatrix="both", then both the P(++) matrix and P(--) matrix are plotted.
Boolean. If TRUE, then confidence envelops are plotted around IRFs and ISRFs.
Type of plotted (1 - alpha) confidence intervals. By default 95-percent confidence intervals are depicted
Color of the plotted curves and confidence envelops. Default is black.
Transparancy of the confidence intervals. Higher values result in more opaque colors for the confidence intervals.
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
Returns a graph.
The default graphic device in R may only display the last graph.
In the plot of the P(++) matrix and the P(--) matrix, the x-axis contains the \(k =(J-1)m\) item steps not pertaining to item j in order of popularity (ascending). Let \(Y_g=1\) indicate that the g-th item step has been taken: i.e. \(Xi \geq y\) and let \(Y_g=0\) indicate that the g-th item step has not been taken: i.e. \(Xi < y\). The \(m\) lines in the plot of the P(++) matrix connect \(P(X_j \geq x, Y_1=1), \dots, P(X_j \geq x, Y_k=1)), x = 1, \dots m\). The \(m\) lines in the plot of the P(--) matrix connect \(P(X_j < x, Y_1=0), \dots, P(X_j < x, Y_k=0)), x = 1, \dots, m\).
If the number of item steps on the x-axis is greater than 10, then the labels are not displayed,
Molenaar, I.W., & Sijtsma, K. (2000) User's Manual MSP5 for Windows [Software manual]. IEC ProGAMMA.
Sijtsma, K., & Molenaar, I. W. (2002) Introduction to nonparametric item response theory. Sage.
Van der Ark, L. A. (2007). Mokken scale analysis in R. Journal of Statistical Software. https://www.jstatsoft.org/article/view/v020i11
# NOT RUN {
data(acl)
Communality <- acl[,1:10]
pmatrix.list <- check.pmatrix(Communality)
plot(pmatrix.list)
summary(pmatrix.list)
# }
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