frostDays: Number of frost days
In rsnotivoli/agroclim: Climatic Indices for Agriculture

Description Usage Arguments Details Value Examples

Calculates the number of frost days within a predefined period.

1	frostDays(mn, dates, iniday = "07-01", endday = "06-30", thres = 0)

`mn`	vector of daily minimum temperature series.
`dates`	vector of dates corresponding with daily temprature series
`iniday`	first day of the year ("dd-mm") when frost occurrence will be considered.
`endday`	last day of the year ("dd-mm") when frost occurrence will be considered.
`thres`	temperature threshold considered to trigger frost occurrence (0 by default).

Despite the logical threshold of temperature is 0 ºC to determine frost occurrence, the argument "thres" is open to change in case of different units of temperature.

A numeric vector with the annual number of frost days is returned.

frostDays(mn = daily_tmin,
           dates = seq.Date(as.Date('1981-01-01'),
                             as.Date('2010-12-31'), by ='day'),
           iniday = '07-01',
           endday = '06-30')