R: Map an item model, item parameters, and person trait score...

rpf.prob {rpf} | R Documentation

## Map an item model, item parameters, and person trait score into a probability vector

### Description

Map an item model, item parameters, and person trait score into a probability vector

### Usage

    rpf.prob(m, param, theta)

### Arguments

`m` | an item model
`param` | item parameters
`theta` | the trait score(s)

### Value

a vector of probabilities. For dichotomous items, probabilities are returned in the order incorrect, correct. Although redundent, both incorrect and correct probabilities are returned in the dichotomous case for API consistency with polytomous item models.

### Examples

    i1 <- rpf.drm()
    i1.p <- rpf.rparam(i1)
    rpf.prob(i1, c(i1.p), -1)   # low trait score
    rpf.prob(i1, c(i1.p), c(0,1))    # average and high trait score

[Package rpf version 0.56.1 Index]