| informationWrightMap {conquestr} | R Documentation |
Plots test information function, relative to ability density, and item locations.
informationWrightMap(
myItems,
myAbilities,
type = "empirical",
minTheta = NA,
maxTheta = NA,
stepTheta = NA,
scaleInfo = 1
)
myItems |
A vector of item deltas. |
myAbilities |
A vector of person abilities. |
type |
A character String. Should the test information be calculated empirically ("empirical" - default) or analytically using moments of distribution ("approx"). |
minTheta |
The smallest value of ability PDF to plot. |
maxTheta |
The largest value of ability PDF to plot. |
stepTheta |
The increment to iterate over the ability PDF. Defaults to 0.01. |
scaleInfo |
A scaling factor to apply to the plot of tesr information. Because ability distribution is a PDF with area one, and a test information function has area L, this can make the plot more interpretable. Defaults to 1. |
A ggplot2 object.
myInfoPlot<- informationWrightMap(runif(10, -2, 3), rnorm(1000, 0, 1), minTheta=-10, maxTheta=10)