agroclim (version 0.3.0)

lastFrost: Mean last frost day

Description

Calculates the last frost day within a predefined period.

Usage

lastFrost(
  mn,
  dates,
  iniday = "07-01",
  endday = "06-30",
  type = "doy",
  thres = 0
)

Value

A numeric vector with annual values is returned.

depending on argument type, the output will be a numeric vector of julian days (type = "doy") or a vector of characters with dates (type = "date").

Arguments

mn

vector of daily minimum temperature series.

dates

vector of dates corresponding with daily temprature series

iniday

first day of the year ("dd-mm-YYYY") when frost occurrence will be considered.

endday

last day of the year ("dd-mm-YYYY") when frost occurrence will be considered.

type

type of output. It can be "doy" for day of the year (julian day) or "date" for data format ("dd-mm").

thres

temperature threshold considered to trigger frost occurrence (0 by default).

Details

The function is able to span over years. If the argument "enddate" is a date earlier than "inidate", the considered period will cover from "inidate" to the end of the year and from the beginning of the next year to "enddate".

Examples

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