plotTIF {GGUM}

Plot test information function (TIF)

Description

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

Usage

plotTIF(IP, Th)

Arguments

IP

Object of class GGUM.

Th

Theta estimates from function Theta.EAP().

Value

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

Details

This function plots the test information function (TIF).

Author(s)

Jorge N. Tendeiro, [e-mail]

Examples

## Not run: 
# 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)

## End(Not run)
## Not run: 
# 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)

## End(Not run)