| icrfG {lazy.irtx} | R Documentation |
Calculation of Item Response Function of Graded Response Items
icrfG(param, theta, smallP = 0, print = 0, plot = 0, debug = 0)
param |
Item Parameter Data Frame |
theta |
Discrete theta values |
smallP |
Minimum value of probability |
print |
= 1 to print result |
plot |
= 1 to plot result |
debug |
= 1 to print intemediate result |
An Example of Item Parameter datastet: maxncat = 5
Note that the subscript of the b-parameter ranges between
1 and ncat-1 (= maxscore) (We set c0=0.)
name ncat A b1 b2 b3 b4
Item1 2 1.0 0.0 . . .
Item2 2 1.0 0.0 . . .
Item3 3 1.5 -1.0 0.0 . .
Item4 4 1.5 -1.0 0.0 1.0 .
Item5 5 1.5 -1.0 0.0 1.0 2.0
list
P length(theta) x sum(ncat) ICRF matrix
PP length(theta) x sum(ncat) ICBRF matrix
Pt length(theta) x nitems item response function
fromP, toP indexes of each ICRF in P
fromPP, toPP indexes of each ICBRF in PP