Adding Annotations to Objects

Annotations, that is, objects of class "annotation", are character vectors with all their elements named. Only one method is defined for this subclass of character vectors, a method for show, that shows the annotation in a nicely formatted way. Annotations of an object can be obtained via the function annotation(x) and can be set via annotation(x)<-value.

Elements of an annotation with names "description" and "wording" have a special meaning. The first kind can be obtained and set via description(x) and description(x)<-value, the second kind can be obtained via wording(x) and wording(x)<-value. "description" elements are used in way the "variable labels" are used in SPSS and Stata. "wording" elements of annotation objects are meant to contain the question wording of a questionnaire item represented by an "item" objects. These elements of annotations are treated in a special way in the output of the coodbook function.

Usage

annotation(x)
# S4 method for ANY
annotation(x)
# S4 method for item
annotation(x)
# S4 method for data.set
annotation(x)
annotation(x)<-value
# S4 method for ANY,character
annotation(x)<-value
# S4 method for ANY,annotation
annotation(x)<-value
# S4 method for item,annotation
annotation(x)<-value
# S4 method for vector,annotation
annotation(x)<-value

description(x)
description(x)<-value

wording(x)
wording(x)<-value

# S4 method for data.set
description(x)
# S4 method for importer
description(x)
# S4 method for data.frame
description(x)
# S4 method for tbl_df
description(x)

Arguments

x

an object

value

a character or annotation object

Value

annotation(x) returns an object of class "annotation", which is a named character. description(x) and wording(x) each usually return a character string. If description(x) is applied to a data.set or an importer object, however, a character vector is returned, which is named after the variables in the data set or the external file.

Examples

vote <- sample(c(1,2,3,8,9,97,99),size=30,replace=TRUE)
labels(vote) <- c(Conservatives         =  1,
                    Labour                =  2,
                    "Liberal Democrats"   =  3,
                    "Don't know"          =  8,
                    "Answer refused"      =  9,
                    "Not applicable"      = 97,
                    "Not asked in survey" = 99
                    )
missing.values(vote) <- c(97,99)
description(vote) <- "Vote intention"
wording(vote) <- "If a general election would take place next tuesday,
                    the candidate of which party would you vote for?"
annotation(vote)
#> description:
#>      Vote intention
#> 
#> wording:
#>      If a general election would take place next tuesday, the candidate of
#>      which party would you vote for?
#> 
annotation(vote)["Remark"] <- "This is not a real questionnaire item, of course ..."
codebook(vote)
#> ================================================================================
#> 
#>    vote 'Vote intention'
#> 
#>    "If a general election would take place next tuesday, the candidate of which
#>    party would you vote for?"
#> 
#> --------------------------------------------------------------------------------
#> 
#>    Storage mode: double
#>    Measurement: nominal
#>    Missing values: 97, 99
#> 
#>    Values and labels              N Valid Total
#>                                                
#>     1   'Conservatives'           8  32.0  26.7
#>     2   'Labour'                  5  20.0  16.7
#>     3   'Liberal Democrats'       2   8.0   6.7
#>     8   'Don't know'              7  28.0  23.3
#>     9   'Answer refused'          3  12.0  10.0
#>    97 M 'Not applicable'          2         6.7
#>    99 M 'Not asked in survey'     3        10.0
#> 
#>    Remark:
#>        This is not a real questionnaire item, of course ...
#>