as.yyww

as.yyyyww

a vector that can be coerced to a date of the form yV (yyww) or YV (yyyyww)

Should the format of <code>x</code> be checked to be in correct 
format before we try to change it? <code>TRUE</code> by default. Set to <code>FALSE</code>
if the format is already checked outside the function to avoid multiple checks 
(that could be time consuming for big data sets).

format_check

Identify, convert and handle dates as used within the Swedish cancer register and associated cancer quality registers in Sweden. Especially the cancer register sometimes use nonstandard date variables where day and/or month can be "00" or were the date format is a mixture of"%Y-%m-%d", "%Y%m%d" and "%y%V" (two digit year and week number according to ISO 8601,which is not completely supported by R).These dates must be approximated to valid dates before being used in for example survival analysis. The package also includes some convenient functions for calculating "lead times" (relying on 'difftime') and introduce a "year" class with relevant S3-methods to handle yearly cohort.

as.yyww: Coerce yyww-variable to a valid date.

Description

Usage

Arguments

Value