trf {irtoys} | R Documentation |
Test response function
Description
Returns the test response function (TRF) of the 3PL (1PL, 2PL) model. The
TRF is the sum of the item response functions (IRF) in a test, and
represents the expected score as a function of the latent variable
\theta
.
Usage
trf(ip, x = NULL)
Arguments
ip |
Item parameters: the output of |
x |
The values of the latent variable ( |
Details
A common use of this function would be to obtain a plot of the TRF.
Value
A list of:
x |
A copy of the argument |
f |
A vector containing the TRF values |
Author(s)
Ivailo Partchev
See Also
Examples
plot(trf(Scored2pl))
[Package irtoys version 0.2.2 Index]