Pulse Documentation

name: op-synth-discrete
description: Exact per-level histogram for an integer column; what a profile reconstructs every u4/u8/u16/u32/u64 field from.
kind: operator
category: SYNTH
operator: discrete
type: reference
applies_to: inspect, predict, manifest
examples_tags: [synth, cohort-analysis]

Use when

Draws whole-number levels at set shares, such as a 1 to 7 rating scale, so each level appears about as often as declared.

Questions it answers:

• How do I generate answers on a 1 to 5 scale where most people choose 4?
• How do I reproduce the exact spread of a rating question?

Use something else:

• normal when the field is a continuous measure.
• weighted_categorical when the levels are text labels.

Params

• values — list of numbers, required, non-empty, strictly ascending.
• weights — list of numbers, default uniform. Non-negative, len(values) long. Raw counts fine — normalised at parse.

Inputs

Field type: — u4/u8/u16/u32/u64 (the arm profile create targets); also legal on f32/f64.

Output

One declared level per row at its own share. Marginal exact — no threshold, no rounding bias.

Gotchas

• The only honest marginal for a coded scale. profile create uses it for every integer column with ≤64 observed levels, ahead of --fit-shape. A clamped normal keeps the mean and flattens the shape: a 1–7 item at 25.26% on level 1 generated 13.73%.
• Over 64 levels the capture ABANDONS it (never truncates) and the field falls back to the clamped normal. The missing discrete key in the profile is the record — no warning, no knob.
• A modelled target is an ORDERED PROBIT. The staircase Q shifts the latent, not the value: direction and ordering carry, scale-point magnitude does not. latentFor refuses a staircase, so the fidelity models section scores both sides on the interval-midpoint probit score rather than inverting.
• Non-ascending or duplicate values → SERVICE_VALIDATION; silent sorting would break Q’s monotonicity and the copula’s rank order.
• A rule reading the field needs no round() guard — the row value already is the stored integer.

See

• Skills: synth-marginals, op-synth-bernoulli, op-synth-weighted-categorical, type-u4