These modifiers are used to select specific months from specific
climate parameters, and potentially transform the selections into
their respective sums or means. The modifiers can be chained
together using '+'.
.range
corresponds to using all specified months
separately, while .sum
and .mean
will use the sums
and means of the specified months. These modifiers also allow to
select specific climatic variables, addressed by name. Thus,
.mean(4:8, "temp")
will select the mean for climate
parameter "temp" for the months April to August. Not only ranges,
but also individual vectors can be used for month specification,
like e.g., .range(c(1, 3, 4, 5)
.
The modifiers can be chained together using the '+' symbol, which
makes it possible to create arbitrarily complex selections of
climate parameters for calibration. E.g., .mean(2:5,
"temp") + .sum(2:5, "prec")
will yield the February-to-May mean
for the variable "temp" and the sum of the variable "prec" for the
same time. While there is no limitation for number of lists that
can be chained together, 'dcc' will not check for meaningful
specifications. Testing smart hypotheses is up the researcher.