Pulse Documentation

name: op-synth-set-bernoulli
description: Multi-select set_* bitmask generation — independent per-option Bernoulli draws, or a joint-structure resample when a paired field is declared.
kind: operator
category: SYNTH
operator: set_bernoulli
type: reference
applies_to: inspect, predict, manifest
examples_tags: [synth, distribution-shape]

Synth distributions emit per-row values; no Response.Components.

Use when

Fills a multi-select answer: each option is ticked on its own at its own rate, such as 40% picking email and 25% SMS.

Questions it answers:

• How do I simulate a tick-all-that-apply question?
• How do I generate which channels each customer has opted into?

Use something else:

• weighted_categorical when each row picks exactly one answer.
• bernoulli when there is only one yes/no flag.

Params

• options — list[string], required. Dictionary entries in bit order (bit i ↔ options[i]). Pre-registers the field’s dictionary at schema-build time — never lazily by first touch, so bit assignment is deterministic.
• frequencies — list[float], default 0.5 each. Per-option P(bit set) in [0, 1]; length must match options.

An option draws independently unless Spec.SetCategoricalPairs / SetNumericPairs / SetSetPairs names it as a captured joint pair’s target — then its bit is resampled from the pair’s conditional probability instead of frequencies[i].

Inputs

Field type: — any set rung, set_u8/u16/u32/u64/u128/u256; options length must not exceed the type’s MaxSetEntries() (8/16/32/64/128/256). The draw is width-agnostic — a member above bit 64 gets the same independent Bernoulli as one below it.

Output

Per-row map[string]bool (every declared option; true = selected), assembled into the bitmask at write time from each selected option’s pre-registered dictionary ID, never by first-encounter order.

Gotchas

• Empty options, frequencies length mismatch, or a frequency outside [0, 1] → SERVICE_VALIDATION.
• options count over MaxSetEntries() → PULSE_IMPORT_SET_OVERFLOW at schema build.
• SpecFromProfile fills this from FieldProfile.Set.Options and wires SetCategoricalPairs/SetNumericPairs/SetSetPairs from Conditional.Set*Pairs only when the paired field also reconstructed to its expected distribution (weighted_categorical / normal / set_bernoulli).
• A profile captured without --conditional has no joint sections — every option draws its own marginal, byte-for-byte the pre-joint behaviour.
• SpecFromProfile carries EVERY captured member, at every rung — FieldProfile.Set.Options is bit-ordered and uncapped below MaxSetEntries(), so a 206-member set_u256 round-trips member-for-member. A translation that stopped at 64 would generate a plausible cohort whose high members are simply never selected.
• Go map iteration order is never used for bit assignment (dictionary pre-populated in options order), so the seeded stream stays byte-identical.

See

• pulse_examples_search tags=[synth]
• Skills: synth-set-fields, type-set-u8, op-synth-weighted-categorical, op-synth-bernoulli