trf: Test response function
In irtoys: A Collection of Functions Related to Item Response Theory (IRT)
trf 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
θ.
Usage
trf(ip, x = NULL)
Arguments
ip
Item parameters: the output of est, or a 3-column matrix
corresponding to its first element, est.
x
The values of the latent variable (θ in the equation
above), at which the IRF will be evaluated. If not given, 99 values spaced
evenly between -4 and +4 will be used, handy for plotting.
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 x
f
A
vector containing the TRF values
Author(s)
Ivailo Partchev
See Also
plot.trf, irf
Examples
plot(trf(Scored2pl))
irtoys documentation built on May 12, 2022, 5:06 p.m.
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| trf | 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 θ.
Usage
trf(ip, x = NULL)
Arguments
ip |
Item parameters: the output of |
x |
The values of the latent variable (θ in the equation above), at which the IRF will be evaluated. If not given, 99 values spaced evenly between -4 and +4 will be used, handy for plotting. |
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
plot.trf, irf
Examples
plot(trf(Scored2pl))
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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