R: Store Discriptive Information About an Object

valueTags {Hmisc} | R Documentation

## Store Discriptive Information About an Object

### Description

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

### Usage

    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`.

### 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.

### 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`

### Author(s)

Charles Dupont

### See Also

`names`, `attributes`

### 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
    x2[1:5]
    dframe <- data.frame(x1, x2)
    Label(dframe)

    ##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'

[Package Hmisc version 4.2-0 Index]