Returns the age-interpolated median of the phase1 references
based on LF & SF in GSED-BGD, GSED-PAK, GSED-TZA. This function is used
to set prior mean under keys "293_0" and "gsed2212".
count_mu_phase1(t)Decimal age, numeric vector
A vector of length length(t) with the median of the GCDG references.
The interpolation is done in two rounds. First round: Calculate D-scores using .gcdg prior-mean, calculate reference, estimate round 1 parameters used in this function. Round 2: Calculate D-score using round 1 estimates as the prior mean (most differences are within 0.1 D-score points), recalculate references, estimate round 2 parameters used in this function.
Round 1: Count model: <= 9MN: 21.3449 + 26.4916 t + 7.0251(t + 0.2) Count model: > 9Mn & <= 3.5 YR: 14.69947 - 12.18636 t + 69.11675(t + 0.92) Linear model: > 3.5 YRS: 61.40956 + 3.80904 t
Round 2: Count model: < 9MND: 20.5883 + 27.3376 t + 6.4254(t + 0.2) Count model: > 9MND & < 3.5 YR: 14.63748 - 12.11774 t + 69.05463(t + 0.92) Linear model: > 3.5 YRS: 61.37967 + 3.83513 t
The working range is 0-3.5 years. After the age of 3.5 years, the function will increase at an arbitrary rate of 3.8 D-score points per year.
Internal function. Called by dscore()
dscore:::count_mu_phase1(0:5)
#> [1] 10.24702 47.56581 64.39981 72.61921 76.72019 80.55532