R/BIFIE.data.select.R

In BIFIEsurvey: Tools for Survey Statistics in Educational Assessment

## File Name: BIFIE.data.select.R
## File Version: 1.23


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# selection variables or datasets in BIFIEcdata objects
BIFIE.data.select <- function( bifieobj, varnames=NULL, impdata.index=NULL )
{
    if ( bifieobj$cdata ){
        stop("Use 'BIFIE.cdata.select' or the general function 'BIFIEdata.select'")
    }
    # retain variable "one"
    varnames0 <- bifieobj$varnames
    if ( ! is.null(varnames) ){
            varnames <- union( varnames, intersect( "one", varnames0) )
    }

    #******** select some imputed datasets
    if ( ! is.null(impdata.index ) ){
        i1 <- impdata.index - 1
        N <- bifieobj$N
        ind <- NULL
        for (ii in i1){
            vec <- ii*N + ( 1:N )
            ind <- c(ind, vec)
        }
        bifieobj$datalistM <- bifieobj$datalistM[ ind,, drop=FALSE]
        bifieobj$Nimp <- length(i1)
    }
    #********* select some variables
    if ( ! is.null(varnames) ){
        dfr1 <- data.frame( "varnames"=bifieobj$varnames, "index"=seq(1,length(bifieobj$varnames) ) )
        dfr1$selectvars <- 1 * ( dfr1$varnames %in% varnames )
        dfr1 <- dfr1[ dfr1$selectvars==1, ]
        bifieobj$datalistM <- bifieobj$datalistM[, dfr1$index, drop=FALSE]
        bifieobj$dat1 <- bifieobj$dat1[, dfr1$index, drop=FALSE]
        bifieobj$varnames <- bifieobj$varnames[ dfr1$index ]
        # process variable list
        bifieobj$variables <- bifieobj$variables[  dfr1$index, ]
    }
    bifieobj$Nvars <- ncol(bifieobj$dat1)
    return(bifieobj)
}
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