xtfrm
Auxiliary Function for Sorting and Ranking
Description
Generic auxiliary function to create a numeric vector sorted in the
same order as input object.
Usage
xtfrm(x)
## Default S3 method:
xtfrm(x)
## S3 method for class 'AsIs':
xtfrm(x)
## S3 method for class 'Date':
xtfrm(x)
## S3 method for class 'difftime':
xtfrm(x)
## S3 method for class 'factor':
xtfrm(x)
## S3 method for class 'POSIXct':
xtfrm(x)
## S3 method for class 'POSIXlt':
xtfrm(x)
## S3 method for class 'Surv':
xtfrm(x)
Arguments
Details
xtfrm is a generic function that is an auxiliary function to
create a numeric vector sorted in the same order as
x.
Because
xtfrm is an internal primitive function, both S3 and S4 methods can
be implemented. Currently, the default method and some methods for other
classes are implemented.
- The default method returns the un-class of x if x is
numeric; otherwise, it returns the rank of x. (The rank is coerced
to a vector).
- "xtfrm.AsIs" removes the "AsIs" class from the
vector of class attributes first, and then calls the method of
xtfrm.
- "xtfrm.Date", "xtfrm.difftime",
"xtfrm.POSIXct", and "xtfrm.POSIXlt" return the
coercion of x to double.
- "xtfrm.factor " returns the coercion of x to integer.
- "xtfrm.numeric_version" calls the utility function
.encode_numeric_version. (For more information about
"xtfrm.numeric_version", see numeric_version.)
- "xtfrm.Surv" returns the order of the columns of a Survival
matrix.
Value
returns a numeric vector of the same length as x.
See Also
Examples
x <- factor(c("R", "G", "B"))
xtfrm(x)
x <- c(2, 4, 8, 5, 1, 9)
xtfrm(x)
x <- c("G", "B", "R")
xtfrm(x)
## date-time objects
x <- as.Date(c("1997/09/13","2010/05/24","2001/07/18"))
xtfrm(x)
x <- as.POSIXct(c("1997/09/13","2010/05/24","2001/07/18"))
xtfrm(x)
x <- as.POSIXlt(c("1997/09/13","2010/05/24","2001/07/18"))
xtfrm(x)
x <- as.difftime(c("01:02:03","04:05:06","07:08:09"))
xtfrm(x)
xtfrm(I(x)) # Example for "AsIs" class
x <- numeric_version(c("2.12.0", "1.4", "2.10.1"))
xtfrm(x)
# Example for "Surv" class
require(survival)
x <- Surv(c(0.1, 0, 3, 1.3), c(3, 24, 7, 3.4),
c(TRUE, FALSE, FALSE, TRUE))
xtfrm(x)