R/gdm_collect_itempars.R

In CDM: Cognitive Diagnosis Modeling

## File Name: gdm_collect_itempars.R
## File Version: 0.07



################################################################
# collect item parameters
gdm_collect_itempars <- function( data, K, D, b, a, TD, thetaDes, irtmodel,
            se.b, se.a, data0)
{
    # collect item parameters
    item <- data.frame( "item"=colnames(data0),
                    "N"=colSums(1-is.na(data0) ) )
    item$M <- colMeans(data0, na.rm=T)
    # b parameters
    se.b[ b < -9999  ] <- NA
    b[ b < -9999  ] <- NA
    se.a[ a < -9999  ] <- NA
    a[ a < -9999  ] <- NA

    for (kk in 1:K){
        item[, paste0( "b.Cat", kk) ] <- b[,kk]
    }
    for (dd in 1:TD){
        if ( irtmodel %in% c("1PL", "2PL") ){
            item[, paste0( "a.", colnames(thetaDes)[dd] ) ] <- a[,dd,1]
        }
        if ( irtmodel %in% c("2PLcat") ){
            for (kk in 1:K){
                item[, paste0( "a.", colnames(thetaDes)[dd], ".Cat", kk ) ] <- a[,dd,kk]
            }
            se.a[ a==-99999  ] <- NA
            a[ a==-99999  ] <- NA
        }
    }
    #--- OUTPUT
    res <- list(item=item, b=b, se.b=se.b, a=a )
    return(res)
}

.gdm.collect.itempars <- gdm_collect_itempars