if (FALSE) {
data(LSAT7)
fulldata <- expand.table(LSAT7)
mod1 <- mirt(fulldata,1,SE=TRUE)
mod2 <- mirt(fulldata,1, itemtype = 'Rasch')
mod3 <- mirt(fulldata,2)
itemplot(mod1, 2)
itemplot(mod1, 2, CE = TRUE)
itemplot(mod1, 2, type = 'info')
itemplot(mod1, 2, type = 'info', CE = TRUE)
mods <- list(twoPL = mod1, onePL = mod2)
itemplot(mods, 1, type = 'RE')
# multidimensional
itemplot(mod3, 4, type = 'info')
itemplot(mod3, 4, type = 'info',
col.regions = colorRampPalette(c("white", "red"))(100))
itemplot(mod3, 4, type = 'infocontour')
itemplot(mod3, 4, type = 'tracecontour')
# polytomous items
pmod <- mirt(Science, 1, SE=TRUE)
itemplot(pmod, 3)
itemplot(pmod, 3, type = 'threshold')
itemplot(pmod, 3, CE = TRUE)
itemplot(pmod, 3, type = 'score')
itemplot(pmod, 3, type = 'score', CE = TRUE)
itemplot(pmod, 3, type = 'infotrace')
itemplot(pmod, 3, type = 'infocat')
# use the directlabels package to put labels on tracelines
library(directlabels)
plt <- itemplot(pmod, 3)
direct.label(plt, 'top.points')
# change colour theme of plots
bwtheme <- standard.theme("pdf", color=FALSE)
plot(pmod, type='trace', par.settings=bwtheme)
itemplot(pmod, 1, type = 'trace', par.settings=bwtheme)
# additional modifications can be made via update().
# See ?update.trellis for further documentation
(plt <- itemplot(pmod, 1))
update(plt, ylab = expression(Prob(theta))) # ylab changed
# infoSE plot
itemplot(pmod, 1, type = 'infoSE')
# uncomment to run interactive shiny applet
# itemplot(shiny = TRUE)
}
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