xxIRT (version 1.0.1)

gen.irt: Generate IRT Object

Description

Create an IRT object with generated values

Usage

gen.irt(n.peo, n.item, thetas = NULL, a = NULL, b = NULL, c = NULL, theta.mu = 0, theta.sig = 1, a.mu = 0, a.sig = 0.15, b.mu = 0, b.sig = 1, c.min = 0, c.max = 0.15)

Arguments

n.peo

the number of people to be generated

n.item

the number of items to be generated

thetas

a vector of ability parameters to be imported

a

a vector/number of a parameters to be imported

b

a vector of b parameters to be imported

c

a vector/number of item c parameters to be imported

theta.mu

the mean of the normal distribution from which thetas are generated

theta.sig

the sd of the normal distribution from which thetas are generated

a.mu

the log mean of the lognormal distribution from which a parameters are generated

a.sig

the log sd of the lognormal distribution from which a parameters are generated

b.mu

the mean of the normal distribution from which b parameters are generated

b.sig

the sd of the normal distribution from which b parameters are generated

c.min

the minumum of the uniform distribution from which c parameters are generated

c.max

the maximum of the uniform distribution from which c parameters are generated

Value

an irt object

Details

In generation, thetas are drawn from the normal distribution, a parameters from the lognormal distribution, b parameters from the normal distribution, and c parameters from the uniform distribution. When parameters are imported, they are not drawn from the distribution.

See Also

Other commons: irt, prob

Examples

gen.irt(10, 5) # generate 10 people, 5 items
gen.irt(10, 5, thetas=seq(.1, 1, length.out=10)) # generate data with given thetas
gen.irt(10, 5, a=.588, c=0)  # generate data with given iteme parameters (Rasch items)