Used to graduate the individuals-years lived by those dying in the interval by the method of Coale et al. (1983).
coale(b1, b4, nMx)Two-element vector of regression coefficients for graduating 1 to 0 age-classes provided in Coale et al. (1983).
Two-element vector of regression coefficients for graduating 4 to 1 age-classes provided in Coale et al. (1983).
Period central death rates = nDx/nKx.