attr_factor: Create factors for variables within a data frame using the...

In amp.dm: Data Management Tools for Pharmacometrics

Create factors for variables within a data frame using the format attribute

Description

This function searches for the 'format' attribute within a data frame, if found it applies the format to that variable. The resulting variable will be a factor useful for plotting and reporting

Usage

attr_factor(data, verbose = TRUE, largestfirst = FALSE)

Arguments

data	the data.frame for which factors should be created
verbose	a logical indicating if datachecks should be printed to console
largestfirst	either a logical or a character vector indicating if the largest group should be the first level (see details)

Details

In order to make this function work the 'format' attribute should be present and should be available as a named vector (e.g. attr(data$GENDER,'format') <- c('0' = 'Male', '1' = 'Female')). If the attribute is found it overwrites the variable with the format applied to it. Be aware that the original levels defined in the format could be lost in this process. The 'largestfirst' argument could be set to a logical which indicates if a for all variables in the dataset, the largest group should be the first level. The argument could also be a character vector indicating for which of the variables in the dataset, the largest group should be the first level. In case you want to set a specific order, this can be done directly in the the format attribute, e.g. attr(data$VAR,'format') <- c('2' = 'level 1', '1' = 'Level 2')

Value

data frame with the formats assigned

Author(s)

Richard Hooijmaijers

See Also

factor, attr_add, attr_xls

Examples

dfrm <- data.frame(GENDER=rep(c(0,1),4),RESULT=rnorm(8))
attr(dfrm$GENDER,'format')   <- c('0' = 'Male', '1' = 'Female')
dfrm <- attr_factor(dfrm)
str(dfrm$GENDER)

amp.dm documentation built on March 13, 2026, 5:08 p.m.