R/xxirt_EAP.R

In alexanderrobitzsch/sirt: Supplementary Item Response Theory Models

## File Name: xxirt_EAP.R
## File Version: 0.117


#--- compute EAP and its standard deviation
xxirt_EAP <- function(p.aj.xi, Theta )
{
    D <- ncol(Theta)
    e1 <- p.aj.xi %*% Theta
    colnames(e1) <- paste0('EAP.Dim', 1L:D)
    e2 <- p.aj.xi %*% Theta^2
    colnames(e2) <- paste0('SD.EAP.Dim', 1L:D)
    e2 <- e2 - e1^2
    res <- cbind( e1, e2)
    res <- res[, rep( c(0,D), D ) + 1L:D ]
    return(res)
}