index_NI: Nesterov Fire Danger Index.
In ozjimbob/ecbtools: Environmental Change Biology Tools

1	index_NI(DewPoint, Temperature, Rain)

`DewPoint`
`Temperature`
`Rain`

##---- 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 (DewPoint, Temperature, Rain) 
{
    Deficit <- Temperature - DewPoint
    G <- 0
    G_list <- c()
    llength <- length(DewPoint)
    for (day in 1:llength) {
        if (Rain[day] > 3) {
            G <- 0
            G_list <- append(G_list, G)
            next
        }
        if (Temperature[day] > 0) {
            G <- G + (Temperature[day] * Deficit[day])
        }
        G_list <- append(G_list, G)
    }
    G_list
  }