BIFIEsurvey (version 1.5-0)

BIFIE.BIFIEdata2BIFIEcdata: Conversion and Selection of BIFIEdata Objects

Description

Functions for converting and selecting objects of class BIFIEdata. The function BIFIE.BIFIEdata2BIFIEcdata converts the BIFIEdata objects in a non-compact form (cdata=FALSE) into an object of class BIFIEdata in a compact form (cdata=TRUE). The function BIFIE.BIFIE2data2BIFIEdata takes the reverse operation. The function BIFIE.BIFIEdata2datalist converts a (part) of the object of class BIFIEdata into a list of multiply-imputed datasets.

Usage

BIFIE.BIFIEdata2BIFIEcdata(bifieobj, varnames = NULL, impdata.index = NULL)

BIFIE.BIFIEcdata2BIFIEdata(bifieobj, varnames = NULL, impdata.index = NULL)

BIFIE.BIFIEdata2datalist(bifieobj, varnames = NULL, impdata.index = NULL)

Arguments

bifieobj

Object of class BIFIEdata

varnames

Variables chosen for the selection

impdata.index

Selected indices of imputed datasets

Value

• An object of class BIFIEdata saved in a non-compact or compact way, see value cdata.

See Also

BIFIE.data

Examples

#############################################################################
# EXAMPLE 1: BIFIEdata conversions using data.timss1 dataset
#############################################################################
data(data.timss1)
data(data.timssrep)

# create BIFIEdata object
bdat1 <- BIFIE.data( data.list=data.timss1 , wgt= data.timss1[[1]]$TOTWGT ,
            wgtrep=data.timssrep[, -1 ])
summary(bdat1)           

# convert BIFIEdata object bdat1 into a BIFIEcdata object with
#  only using the first three datasets and a variable selection
bdat2 <- BIFIE.BIFIEdata2BIFIEcdata( bifieobj=bdat1 , varnames=bdat1$varnames[ c(1:7,10) ] )

# convert bdat2 into BIFIEdata object and only use the first three imputed datasets
bdat3 <- BIFIE.BIFIEcdata2BIFIEdata( bifieobj=bdat2 , impdata.index=1:3 )

# object summaries
summary(bdat1)
summary(bdat2)
summary(bdat3)		

#############################################################################
# EXAMPLE 2: Extract unique elements in BIFIEdata object
#############################################################################

data(data.timss1)
data(data.timssrep)

# create BIFIEdata object
bifieobj <- BIFIE.data( data.list=data.timss1 , wgt= data.timss1[[1]]$TOTWGT ,
            wgtrep=data.timssrep[, -1 ])
summary(bifieobj)

# define variables for which unique values should be extracted
vars <- c( "female" , "books" ,"ASMMAT" )
# convert these variables from BIFIEdata object into a list of datasets
bdatlist <- BIFIE.BIFIEdata2datalist( bifieobj , varnames = vars )
# look for unique values in first dataset for variables
values <- lapply( bdatlist[[1]] , FUN = function(vv){
                sort( unique( vv ) ) } )
# number of unique values in first dataset
Nvalues <- lapply( bdatlist[[1]] , FUN = function(vv){
                length( unique( vv ) ) } )
# number of unique values in all datasets
Nvalues2 <- lapply( vars , FUN = function(vv){
    #vv <- vars[1]
    unlist( lapply( bdatlist , FUN = function(dd){
                length( unique( dd[,vv]  ) )
                        }    )     )
                    } )
# --> for extracting the number of unique values using BIFIE.by and a user
#     defined function see Example 1, Model 3 in "BIFIE.by"