R/offset_values_extract.R

In mdmb: Model Based Treatment of Missing Data

## File Name: offset_values_extract.R
## File Version: 0.09

offset_values_extract <- function(formula, data )
{
    # Xdes <- stats::model.matrix( formula=formula, data=data )
    # N <- nrow(Xdes)
    Xdes2 <- stats::model.frame( formula=formula, data=data )
    ind_offset <- attr( attr(Xdes2,"terms"), "offset" )
    N <- nrow(Xdes2)
    if ( length(ind_offset) > 0 ){
        offset_values <- Xdes2[, ind_offset ]
    } else {
        offset_values <- rep(0,N)
    }
    return(offset_values)
}