Store Descriptive Information About an Object

Functions get or set useful information about the contents of the object for later use.

valueTags(x)
valueTags(x) <- value

valueLabel(x)
valueLabel(x) <- value

valueName(x)
valueName(x) <- value

valueUnit(x)
valueUnit(x) <- value

Arguments

x

an object

value

for valueTags<- a named list of value tags. a character vector of length 1, or NULL.

Value

valueTag returns NULL or a named list with each of the named values name, label, unit set if they exists in the object.

For valueTag<- returns list

For valueName, valueLable, and valueUnit returns NULL or character vector of length 1.

For valueName<-, valueLabel<-, and valueUnit returns value

Details

These functions store the a short name of for the contents, a longer label that is useful for display, and the units of the contents that is useful for display.

valueTag is an accessor, and valueTag<- is a replacement function for all of the value's information.

valueName is an accessor, and valueName<- is a replacement function for the value's name. This name is used when a plot or a latex table needs a short name and the variable name is not useful.

valueLabel is an accessor, and valueLabel<- is a replacement function for the value's label. The label is used in a plots or latex tables when they need a descriptive name.

valueUnit is an accessor, and valueUnit<- is a replacement function for the value's unit. The unit is used to add unit information to the R output.

See also

names, attributes

Author

Charles Dupont

Examples

age <- c(21,65,43)
y   <- 1:3
valueLabel(age) <- "Age in Years"
plot(age, y, xlab=valueLabel(age))



x1 <- 1:10
x2 <- 10:1
valueLabel(x2) <- 'Label for x2'
valueUnit(x2) <- 'mmHg'
x2
#> Label for x2 [mmHg] 
#>  [1] 10  9  8  7  6  5  4  3  2  1
x2[1:5]
#> Label for x2 [mmHg] 
#> [1] 10  9  8  7  6
dframe <- data.frame(x1, x2)
Label(dframe)
#> label(x1)	<- ''
#> label(x2)	<- 'Label for x2'


##In these examples of llist, note that labels are printed after
##variable names, because of print.labelled
a <- 1:3
b <- 4:6
valueLabel(b) <- 'B Label'