Reject Zero Division

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Summary

EditUnder reviewWhat this benchmark means

README.md

Public entries: Python and R. Passing coverage requires an installed inventory.

Goal: work out PCHG, the percent change from baseline, from the collected result in AVAL and its baseline in BASE.

Input: laboratory results with baseline values from LB, carrying the collected numeric result (LBSTRESN) and the baseline it is compared with (LBBLRESN).

Variables:

AVAL would be the collected numeric result, taken from LBSTRESN.
BASE would be the baseline it is compared with, taken from LBBLRESN.
PCHG would be the change from baseline as a percentage of it, worked out as 100 * (AVAL - BASE) / BASE; missing when either value is missing.

Note: a zero baseline leaves the percentage with no value. Leaving it missing would assume a rule the request never stated, so the run fails and no artifact is accepted.

How to fix

If the intended result is missing when BASE is zero, guard the denominator explicitly with NULLIF:

derivation: "100 * (AVAL - BASE) / NULLIF(BASE, 0)"

NULLIF(BASE, 0) returns missing for a zero baseline. Missing then propagates through the division, so PCHG is missing for that row instead of raising division_by_zero; nonzero baselines retain the original calculation.

Expected failure

Editthe run is rejected; no artifact is accepted

expected/error.yaml

phase: derivation
condition: division_by_zero
rule: FORMULA-15

expected/error.yaml

phase: derivation
condition: division_by_zero
spec_paths:
  - columns.PCHG.derivation
rule: FORMULA-15
context:
  expr: "100 * (AVAL - BASE) / BASE"
  keys:
    - STUDYID: PILOT7
      USUBJID: P7-742
      PARAMCD: ALT

YAML specification

1 spec file

spec.yaml

Edit44 lines

1yamaa: "1.0"2type: spec3model: ADaM4domain: ADLB5keys: [STUDYID, USUBJID, PARAMCD]6input:7  LB: input/lb.csv89output:10  path: adlb.csv11  columns: [STUDYID, USUBJID, PARAMCD, AVAL, BASE, PCHG]1213columns:14  - name: STUDYID15    type: str16    label: Study Identifier17    derivation: LB.STUDYID1819  - name: USUBJID20    type: str21    label: Unique Subject Identifier22    derivation: LB.USUBJID2324  - name: PARAMCD25    type: str26    label: Parameter Code27    derivation: LB.LBTESTCD2829  - name: AVAL30    type: float31    label: Analysis Value32    derivation: LB.LBSTRESN3334  - name: BASE35    type: float36    label: Baseline Value37    derivation: LB.LBBLRESN3839  - name: PCHG40    type: float41    label: Percent Change from Baseline42    # Missing when AVAL or BASE is missing. A zero BASE stops the run with43    # a division by zero, since no rule says what the result should be.44    derivation: "100 * (AVAL - BASE) / BASE"

Inputs

Under review1 source file

input/lb.csv

Edit2 rows

input/lb.csv
STUDYID	USUBJID	LBTESTCD	LBSTRESN	LBBLRESN
PILOT7		ALT	42	35
PILOT7		ALT	38	0

Unexpected Output

Under reviewNo artifact is produced

No fixture files in this directory.

Shaded columns are derived— = missing value

Human review and assessment

Dataset Name	Variable Name	Variable Label	Type	Computational Method	Origin
ADLB	STUDYID	Study Identifier	character	Copy value from LB.STUDYID.	Predecessor
ADLB	USUBJID	Unique Subject Identifier	character	Copy value from LB.USUBJID.	Predecessor
ADLB	PARAMCD	Parameter Code	character	Copy value from LB.LBTESTCD.	Predecessor
ADLB	AVAL	Analysis Value	numeric	Copy value from LB.LBSTRESN.	Predecessor
ADLB	BASE	Baseline Value	numeric	Copy value from LB.LBBLRESN.	Predecessor
ADLB	PCHG	Percent Change from Baseline	numeric	Compute 100 * (AVAL - BASE) / BASE.	Derived

Version	Date	Author	Description
1.7	2026-10-20	yamaa docs build	Read a specification in the 1.0 surface as its 0.5 counterpart; state that missing values stay missing where a mapping declares no missing handler, and leave out a declared missing answer that restates a handler's default
1.6	2026-10-17	yamaa docs build	Describe collected date parts written as ISO 8601 date text and times of day counted in seconds since midnight
1.5	2026-10-17	yamaa docs build	Name collected precision in words instead of letter codes; state imputation fallbacks, minimum source precision, bounds ignored outside the collected period, and invalid text with no handler as an error; describe date and datetime shifts, imputation flag codes, and partial text giving no date part
1.4	2026-10-15	yamaa docs build	State datetime precision codes through the hour and minute, and complete only the time parts a collected datetime lacks
1.3	2026-09-29	yamaa docs build	Show study codelist names, external dictionaries, and ISO 8601 formats in variable rows; list the document's codelist values and metadata
1.2	2026-09-29	yamaa docs build	Classify ADaM copies from a declared input as Predecessor and recodes as Derived, and SDTM recodes of locally derived columns as Derived
1.1	2026-09-29	yamaa docs build	Resolve lookups into the donor record they select, and give every derivation shape a plain-language rule instead of its raw YAML
1.0		yamaa docs build	Initial generation from spec.yaml

How to fix

input/lb.csv

Your review

Mapping spec