agroclim (version 0.1.0)

firstTemp: 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).

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").

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

# NOT RUN {

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)
# }