index_KBDI: Keech-Byram Drought Index.
In ozjimbob/ecbtools: Environmental Change Biology Tools

1	index_KBDI(Temperature, Rain, MAP = sum(Rain)/length(Rain/365.25))

`Temperature`
`Rain`
`MAP`

##---- Should be DIRECTLY executable !! ----
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function (Temperature, Rain, MAP = sum(Rain)/length(Rain/365.25)) 
{
    KBDI <- 200
    KBDI_list <- c()
    llength <- length(Temperature)
    for (day in 1:llength) {
        pKBDI <- KBDI
        KBDI <- KBDI - Rain[day]
        if (KBDI < 0) {
            KBDI <- 0
        }
        todayET <- lookupET(pKBDI, Temperature[day], MAP)
        KBDI <- KBDI + todayET
        KBDI_list <- append(KBDI_list, KBDI)
    }
    KBDI_list
  }