ym_get_wateryear: Get the water year from a year-month (yearmon) value
Description
ym_get_wateryear() returns the water year (assumed to be October -
September) from a zoo::yearmon object.
Usage
ym_get_wateryear(ym)
getWYFromYearmon(ym)
Arguments
ym
An object of class zoo::yearmon, or something that can be
successfully converted to zoo::yearmon.
Value
The water year as a numeric.
Details
If the argument is not already a yearmon object, it will attempt to convert
it to a zoo::yearmon. This may result in unexpected results. For example,
the string "12-1-1906" can be converted to a zoo::yearmon, however, it
will not convert to "Dec 1906" as you might desire. It will convert to
"Jan 0012" since it is not a format expected by zoo::as.yearmon().
Therefore, a warning is posted when the function attempts to convert to
zoo::yearmon, and it is safer to ensure ym is already a zoo::yearmon.