AddMonthsYM: Add a Month to a Date in YearMonth Format
Description
The representation of year and month information in YYYYYMM format as an integer is sometimes a useful and efficient data structure. Adding a number of months to such a date is not quite catchy, however, since the date structure is to be retained. For example, 201201 - 2 [months] is expected to result in 201111 instead of 201199. AddMonthsYM does this job.
Usage
AddMonthsYM(x, n)
Value
a vector of class integer with the same dimension as x, containing the transformed dates.
Arguments
x
a vector of integers, representing the dates in the format YYYYMM, to which a number of months has to be added.
n
the number of months to be added. If n is negative the months will be subtracted.
Author
Andri Signorell <andri@signorell.net>, based on code by Roland Rapold
Details
All parameters will be recyled if necessary. The therefore used function mapply will display a warning, if the longer argument is not a multiple of the length of the shorter one.