firstTemp: Mean first day with a temperature over a threshold

In agroclim: Climatic Indices for Agriculture

Mean first day with a temperature over a threshold

Description

Calculates the first day, within a predefined period, with a temperature over a threshold

Usage

firstTemp(
  mx,
  dates,
  iniday = "01-01",
  endday = "09-01",
  type = "doy",
  thres = 35
)

Arguments

mx	vector of daily (usually maximum) 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.
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 occurrence (+35 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".

Value

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").

Examples

firstTemp(mx = daily_tmax,
            dates = seq.Date(as.Date('1981-01-01'),
                             as.Date('2010-12-31'), by ='day'),
            iniday = '01-01',
            endday = '01-09',
            type = 'doy',
            thres = 35)

agroclim documentation built on Oct. 14, 2022, 9:05 a.m.