setnames: Modify column names for ffdf, cohort or data.table objects

In CALIBERdatamanage: Data Management Tools for CALIBER Datasets

Description

A version of the setnames data.table function for ffdf data frames or cohort objects.

Usage

setnames(x, old, new)
## S3 method for class 'data.table'
setnames(x, old, new)
## S3 method for class 'cohort'
setnames(x, old, new)
## S3 method for class 'ffdf'
setnames(x, old, new)

Arguments

x	A data.table, cohort or ffdf object
old	Old column names or positions, or a vector of all new column names if new is missing.
new	New column names

Details

Defines 'setnames' as a generic function. For data.table objects, it dispatches the setnames method in the data.table package. For cohort objects, it also updates the description table and idcolname. For FFDF objects, the object is not modified by reference but the modified object is returned.

Value

Invisibly returns the modified object. If it is a data.table, it is also updated by reference.

Examples

COHORT <- cohort(data.table(anonpatid = 1:3, indexdate = as.IDate(c("2012-1-3", 
	"2012-1-2", "2010-1-9"))))
FFDFCOHORT <- as.ffdf(COHORT)

# Data table cohort does not need assignment for changing names
print(COHORT)
setnames(COHORT, c('anonpatid', 'indexdate'), c('id', 'startdate'))
print(COHORT)

print(FFDFCOHORT)
FFDFCOHORT <- setnames(FFDFCOHORT, c('anonpatid', 'indexdate'), c('id', 'startdate'))
print(FFDFCOHORT)

CALIBERdatamanage documentation built on Nov. 23, 2021, 3 p.m.