agroclim (version 0.1.0)

hi: Huglin Heliothermal Index (HI)

Description

Huglin Heliothermal Index (HI). Useful as a zoning tool (Huglin 1978).

Usage

hi(mx, mn, dates, lati)

Arguments

mx

vector of daily maximum temperature series.

mn

vector of daily minimum temperature series.

dates

vector of dates corresponding with daily temprature series

lati

numeric value indicating the latitude of location.

Value

A numeric vector with annual values is returned.

Details

Depending on the latitude, the function detects the hemisphere and considers growing season from 1st April to 30rd September (northern hemisphere) or from 1st October to 31st March (southern hemisphere).

References

Huglin P. (1978) Nouveau mode d'evaluation des possibilities heliothermiques d'un milieu viticole. CR Acad Agr 64: 1117<U+2013>1126

Examples

# NOT RUN {
  hi(mx = daily_tmax,
    mn = daily_tmin,
    dates = seq.Date(as.Date('1981-01-01'),
            as.Date('2010-12-31'), by ='day'),
            lati = 42)

# }