This function takes a dataframe of heat waves, as created by
gen_hw_set, and calculates the total number of heat wave days in
the dataframe (sum of the number of days in each heat wave for all heat waves
in the dataset).
Usage
heatwave_days(hw_datafr)
Arguments
hw_datafr
A dataframe of heat waves and their characteristics, as
created by gen_hw_set
Value
A numeric value with the number of heat wave days in a dataframe
of heat waves, as generated by gen_hw_set.