# Store Descriptive Information About an Object Functions get or set useful information about the contents of the object for later use. ```r 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`. ## Returns `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` ## Examples ```r 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' ``` ## Author(s) Charles Dupont

valueTags function