Extract measurements that can function as date zero

This function scans the tgt object, and finds the observation pairs used by the calculate_advice_xxx() functions.

Usage

calculate_screening_doms(tgt, ynames = c("hgt", "wgt", "hdc"), na.omit = TRUE)

Arguments

tgt

A list with elements psn and xyz

ynames

Character vector identifying the measures to be screened. By default, ynames = c("hgt", "wgt", "hdc").

na.omit

A logical indicating whether records with a missing x (age) or y (yname) should be removed. Defaults to TRUE.

Value

A list with length(ynames) elements. Each list element is another list with elements dom0 (back-calculated dates of measurement, vector, reverse time), age0 (decimal age), y0 (measurement), z0 (Z-score equivalent) and

• for weight - h0, as well as similar quantities dom1, age1, y1, z1 and h1 for the upper part of the pair.

Details

This function implements the "x1_last" strategy for choosing pairs. This strategy selects the last observation as x1 and forms pairs with every earlier observation.

Note

Internal function. Not to be called directly.

Examples

if (FALSE) { # \dontrun{
growthscreener:::calculate_screening_doms(target)
} # }