items {memisc} | R Documentation |
Objects of class item
are data vectors with additional information
attached to them like ``value labels'' and ``user-defined missing values''
known from software packages like SPSS or Stata.
## The constructor for objects of class "item" ## more convenient than new("item",...) ## S4 method for signature 'numeric': as.item(x, labels=NULL, missing.values=NULL, valid.values=NULL, valid.range=NULL, value.filter=NULL, measurement=NULL, annotation=attr(x,"annotation"), ... ) ## S4 method for signature 'character': as.item(x, labels=NULL, missing.values=NULL, valid.values=NULL, valid.range=NULL, value.filter=NULL, measurement=NULL, annotation=attr(x,"annotation"), ... ) ## S4 method for signature 'logical': as.item(x,...) # x is first coerced to integer, # arguments in ... are then passed to the "numeric" # method. ## S4 method for signature 'factor': as.item(x,...) ## S4 method for signature 'ordered': as.item(x,...) ## S4 method for signature 'double.item': as.item(x, labels=NULL, missing.values=NULL, valid.values=NULL, valid.range=NULL, value.filter=NULL, measurement=NULL, annotation=attr(x,"annotation"), ... ) ## S4 method for signature 'integer.item': as.item(x, labels=NULL, missing.values=NULL, valid.values=NULL, valid.range=NULL, value.filter=NULL, measurement=NULL, annotation=attr(x,"annotation"), ... ) ## S4 method for signature 'character.item': as.item(x, labels=NULL, missing.values=NULL, valid.values=NULL, valid.range=NULL, value.filter=NULL, measurement=NULL, annotation=attr(x,"annotation"), ... )
x |
for as.item methods,
any atomic vector; for the as.character , as.factor ,
as.integer , as.double , a vector with class "item" ;
for the unique ,
summary , str , print , [ , and <-
methods, a vector with class labelled .
|
labels |
a named vector of the same mode as x . |
missing.values |
either a vector of the same mode as x ,
or a list with components "values" ,
vector of the same mode as x (which defines individual missing values)
and "range" a matrix with two rows with
the same mode as x (which defines a range of missing values),
or an object of class "missing.values" .
|
valid.values |
either a vector of the same mode as x ,
defining those values of x that are to be considered as valid,
or an object of class "valid.values" . |
valid.range |
either a vector of the same mode as x and length 2,
defining a range of valid values of x ,
or an object of class "valid.range" . |
value.filter |
an object of class "value.filter" , that is, of
classes "missing.values" , "valid.values" , or "valid.range" . |
measurement |
level of measurement; one of "nominal", "ordinal", "interval", or "ratio". |
annotation |
a named character vector,
or an object of class "annotation" |
... |
further arguments, ignored. |
annotation
labels
value.filter
x <- as.item(rep(1:5,4), labels=c( "First" = 1, "Second" = 2, "Third" = 3, "Fourth" = 4, "Don't know" = 5 ), missing.values=5, annotation = c( description="test" )) str(x) summary(x) as.numeric(x) test <- as.item(rep(1:6,2),labels=structure(1:6, names=letters[1:6])) test test == 1 test != 1 test == "a" test != "a" test == c("a","z") test != c("a","z") test test codebook(test) Test <- as.item(rep(letters[1:6],2), labels=structure(letters[1:6], names=LETTERS[1:6])) Test Test == "a" Test != "a" Test == "A" Test != "A" Test == c("a","z") Test != c("a","z") Test Test as.factor(test) as.factor(Test) as.numeric(test) as.character(test) as.character(Test) as.data.frame(test)[[1]]