Two-milestone windows for a guided solve

Builds the {y_k, last} windows the pairs stage of solve_guided() solves: each interior milestone paired with the horizon's last milestone, so every subproblem optimises one milestone's expansion while still seeing the end state. The guided counterpart of horizon_windows(), which slices a horizon into CONSECUTIVE windows instead.

The focus interval is widened to cover the years up to the endpoint, so the window's period lengths span the calendar (pPeriodLen is row-local, so a bare row slice would leave the intervening years unweighted).

Usage

guided_windows(
  horizon,
  direction = c("backward", "forward"),
  include_base = FALSE
)

Arguments

horizon

a horizon object with at least two milestone intervals.

direction

"backward" (default) walks the last interior milestone down to the first, so each step's future is already decided; "forward" walks up from the base year.

include_base

logical, include the base-year milestone as a focus window. FALSE (default) leaves the base year to the base stage, which pins it as stock.

Value

a list of window specs: horizon, focus (the milestone being decided) and endpoint.

See also

solve_guided(), horizon_windows()

Examples

h <- topia$modules$horizons$base

# backward guidance: the endpoint first, then each neighbouring pair
w <- guided_windows(h)
vapply(w, function(x) x$horizon@name, character(1))
#> [1] "g_2040_2050" "g_2030_2050"

# forward instead, including the base period
vapply(guided_windows(h, direction = "forward", include_base = TRUE),
       function(x) x$horizon@name, character(1))
#> [1] "g_2025_2050" "g_2030_2050" "g_2040_2050"