R/mcmc_confint.R

In sirt: Supplementary Item Response Theory Models

## File Name: mcmc_confint.R
## File Version: 0.11

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# confidence interval
mcmc_confint <- function( mcmcobj, parm, level=.95, exclude="deviance" )
{
    mcmcobj <- mcmcobj[, ! ( colnames(mcmcobj) %in% exclude ) ]
    if ( ! missing(parm) ){
        mcmcobj <- mcmcobj[,parm]
    }
    q1 <- ( 1 - level ) / 2
    h1 <- apply( mcmcobj, 2, stats::quantile, q1 )
    q2 <- 1 - ( 1 - level ) / 2
    h2 <- apply( mcmcobj, 2, stats::quantile, q2 )
    res <- data.frame( h1, h2)
    colnames(res)[1] <- paste0( round( 100*q1,1 ), " %")
    colnames(res)[2] <- paste0( round( 100*q2,1 ), " %")
    rownames(res) <- colnames(mcmcobj)
    return(res)
}
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