This is a common approximation of lifetable exposure: All persons surviving to the end of the interval time the interval width, plus all those that died in the interval multiplied by their average time spent in the interval.
lt_id_lda_L(lx, ndx, nax, AgeInt)
| lx | numeric. Vector of age-specific lifetable survivorship. |
|---|---|
| ndx | numeric. Vector of lifetable deaths, summing to radix of |
| nax | numeric. Vector of average time spent in interval by those dying in interval. |
| AgeInt | integer. Vector of age class widths. |
nLx numeric vector of lifetable exposure.
There is no checking of equal vector lengths at this time.
Preston S, Heuveline P, Guillot M (2000). Demography: measuring and modeling population processes. Wiley-Blackwell.