R/mi_dstat.R

In miceadds: Some Additional Multiple Imputation Functions, Especially for 'mice'

## File Name: mi_dstat.R
## File Version: 0.06
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# d effect size for missingness indicators
mi_dstat <- function(dat){
    resp <- is.na(dat)
    # means of missing data
    miss_vars <- colnames(resp)[ colMeans( resp ) > 0 ]
    MV <- length(miss_vars)
    V <- ncol(dat)

    dstat <- matrix( 0, nrow=MV, ncol=V )
    rownames(dstat) <- miss_vars
    colnames(dstat) <- colnames(dat)

    for (vv in 1:MV){
        # vv <- 5
        dat_vv0 <- dat[  resp[, miss_vars[vv]  ],, drop=FALSE ]
        dat_vv1 <- dat[ ! resp[, miss_vars[vv]  ],, drop=FALSE ]
        m0 <- colMeans( dat_vv0, na.rm=TRUE )
        m1 <- colMeans( dat_vv1, na.rm=TRUE )
        sd0 <- apply( dat_vv0, 2, stats::sd, na.rm=TRUE)
        sd1 <- apply( dat_vv1, 2, stats::sd, na.rm=TRUE)
        d <- (m0-m1) / sqrt( ( sd0^2 + sd1^2 ) / 2 )
        dstat[vv,] <- d
    }
    return(dstat)
}
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