Construct full target quantities from a selection — ledgr_target

ledgr_target_quantity() converts a selection into a full-universe ledgr_target that holds the same fixed quantity of every selected instrument. Selected eligible instruments get qty; every other eligible instrument gets zero. Use it for rules such as "hold 10 shares of each instrument that passes the condition"; use ledgr_weight_equal() and ledgr_target_rebalance() instead when positions should be sized from account equity.

Usage

ledgr_target_quantity(selection, ctx, qty)

Arguments

selection: A ledgr_selection object.
ctx: ledgr strategy context.
qty: One finite, non-negative target quantity for each selected instrument.

Value

A full-universe ledgr_target object.

Details

Missing decisions are settled by the selection, not here: build the selection with ledgr_selection(ctx, where = ..., missing = "exclude") when a missing value, such as a feature still in warmup, should mean "not selected".

In an availability-aware run, every ineligible instrument, a held nonmember or a target-restricted member, keeps its current quantity, exactly as ledgr_target_rebalance() preserves it. The selection may name any instrument on the decision axis, but may select eligible instruments only.

Error class: ledgr_invalid_strategy_helper when selection is not a ledgr_selection, names an instrument outside the decision axis, selects an ineligible instrument, or when qty is not one finite, non-negative number. Negative quantities stay refused until short-selling semantics are defined.

Articles

Strategy helper pipelines: vignette("strategy-development", package = "ledgr") system.file("doc", "strategy-development.html", package = "ledgr")

Examples

selection <- ledgr_selection(c(AAA = TRUE, BBB = FALSE),
                             universe = c("AAA", "BBB"))
ctx <- list(universe = c("AAA", "BBB"))
ledgr_target_quantity(selection, ctx, qty = 10)
#> <ledgr_target> [2 assets]
#> non-NA: 2/2
#> AAA BBB 
#>  10   0