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GGUM (version 0.5)

plotTIF: Plot test information function (TIF)

Description

plot.TIF plots the TIF for the GUM and the GGUM.

Usage

plotTIF(IP, Th)

Value

The function returns the (x, y) coordinates of the TIF.

Arguments

IP

Object of class GGUM.

Th

Theta estimates from function Theta.EAP().

Author

Jorge N. Tendeiro, tendeiro@hiroshima-u.ac.jp

Details

This function plots the test information function (TIF).

Examples

Run this code
if (FALSE) {
# For GUM:
# Generate data
#   (toy example: Too few items (due to computation time constraints) for 
#   accurate estimation of person parameters; larger number of items is 
#   required in practice):
gen1 <- GenData.GGUM(400, 5, 3, "GUM", seed = 139)
# Fit the GUM:
fit1 <- GUM(gen1$data, 3)
th1  <- Theta.EAP(fit1)
# Plot TIF:
plotTIF(fit1, th1)
}
if (FALSE) {
# For GGUM:
# Generate data:
set.seed(1); C <- sample(3:5, 10, replace = TRUE)
gen2 <- GenData.GGUM(2000, 10, C, "GGUM", seed = 156)
# Fit the GGUM:
fit2 <- GGUM(gen2$data, C)
th2  <- Theta.EAP(fit2)
# Plot TIF:
plotTIF(fit2, th2)
}

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