A Column Default Reads Its Own Driver Beside Another Driver's Groups

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Summary

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README.md

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

Goal: show that a column's stated default may read a field of a row template's driver when no template groups that driver, even though another template groups a different input: clinic measurements take their visit from the clinic record, while home readings are averaged per subject and study day (VSDY).

Input: one spec.yaml with two row templates. clinic keeps each clinic measurement (input/clinic.csv: one per visit, with the visit name, study day and systolic blood pressure). home builds one record per subject and study day from the home readings (input/home.csv: study day and systolic blood pressure, several possible on one day).

Variables:

VSCAT is CLINIC for a clinic measurement and HOME for a day of home readings.
VSSTRESN is the systolic blood pressure: the measurement itself on a clinic record, and the mean of the day's readings on a home record.
VSDRVFL is Y on a home record, whose result is computed from the day's readings, and blank on a clinic record.
VISIT is the visit of the clinic measurement, stated once by the column for every template. The home template states its own blank value, so only clinic records read it, each from its own measurement.

Note: grouping belongs to the driver a template groups. The home template's groups limit what a home record reads from the home readings and say nothing about a clinic field, so the column reading the clinic record would be refused only by a template that groups the clinic measurements without that field.

YAML specification

1 spec file

spec.yaml

Edit58 lines

1yamaa: "1.0"2type: spec3model: SDTM4domain: VS5keys: [USUBJID, VSCAT, VSDY]6input:7  CLINIC: {path: input/clinic.csv, types: {VSDY: int, SYSBP: int}}8  HOME: {path: input/home.csv, types: {VSDY: int, SYSBP: int}}910output:11  path: vs.csv12  columns: [USUBJID, VSCAT, VSSTRESN, VSDRVFL, VISIT, VSDY]1314columns:15  - {name: USUBJID, type: str, label: Unique Subject Identifier}16  - {name: VSCAT, type: str, label: Category for Vital Signs}1718  - name: VSSTRESN19    type: float20    label: Numeric Result/Finding in Standard Units2122  - {name: VSDRVFL, type: str, label: Derived Flag}2324  # The visit of the clinic measurement, read from its own record. Only the25  # clinic template completes it here; the home template states its own26  # value, so the home readings grouped by day do not bear on this read.27  - name: VISIT28    type: str29    label: Visit Name30    derivation: CLINIC.VISIT3132  - {name: VSDY, type: int, label: Study Day of Vital Signs}3334rows:35  # Each blood pressure measured at a clinic visit.36  - id: clinic37    dataset: CLINIC38    derivations:39      USUBJID: CLINIC.USUBJID40      VSCAT: "'CLINIC'"41      VSSTRESN: CLINIC.SYSBP42      VSDRVFL: null43      VSDY: CLINIC.VSDY4445  # One record per subject and day from the readings taken at home, holding46  # the mean of the day's readings. A day of home readings belongs to no47  # visit.48  - id: home49    dataset: HOME50    group_by: [HOME.USUBJID, HOME.VSDY]51    derivations:52      USUBJID: HOME.USUBJID53      VSCAT: "'HOME'"54      VSSTRESN:55        aggregate: "MEAN(HOME.SYSBP)"56      VSDRVFL: "'Y'"57      VISIT: null58      VSDY: HOME.VSDY

Inputs

Under review2 source files

input/clinic.csv

Edit4 rows

input/clinic.csv
VISIT	VSDY	SYSBP
BASELINE	1	132
WEEK 2	15	128
BASELINE	1	145
WEEK 2	15	141

input/home.csv

Edit4 rows

input/home.csv
USUBJID	VSDY	SYSBP
	8	130
	8	127
	9	124
	15	136

Expected output

Under review7 expected rows

expected/vs.csv

Edit7 rows

expected/vs.csv
VSCAT	VSSTRESN	VSDRVFL	VISIT	VSDY
CLINIC	132	—	BASELINE	1
CLINIC	128	—	WEEK 2	15
CLINIC	145	—	BASELINE	1
CLINIC	141	—	WEEK 2	15
HOME	128.5	Y	—	8
HOME	124	Y	—	9
HOME	136	Y	—	15

Shaded columns are derived— = missing value

Human review and assessment

Variable Name	Variable Label	Type	Origin	Conversion Definition	Variable Type	Variable Order
USUBJID	Unique Subject Identifier	Char	Derived	Set per constructed row; see the Row construction sheet.	SDTM	1
VSCAT	Category for Vital Signs	Char	Derived	Set per constructed row; see the Row construction sheet.	SDTM	2
VSSTRESN	Numeric Result/Finding in Standard Units	Num	Derived	Set per constructed row; see the Row construction sheet.	SDTM	3
VSDRVFL	Derived Flag	Char	Derived	Set per constructed row; see the Row construction sheet.	SDTM	4
VISIT	Visit Name	Char	Collected	Copy value from CLINIC.VISIT.	SDTM	5
VSDY	Study Day of Vital Signs	Num	Derived	Set per constructed row; see the Row construction sheet.	SDTM	6

Template	Include when	USUBJID	VSCAT	VSSTRESN	VSDRVFL	VSDY	VISIT
clinic		Copy CLINIC.USUBJID	Constant "CLINIC"	Copy CLINIC.SYSBP	Constant "None"	Copy CLINIC.VSDY	None
home		Copy HOME.USUBJID	Constant "HOME"	Aggregate MEAN(HOME.SYSBP) over records matching on the shared output keys	Constant "Y"	Copy HOME.VSDY	Constant "None"

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

R

Edit3 lines

1library(yamaa)23yamaa_spec("spec.yaml")$run()$output

Python

Edit3 lines

1import yamaa23yamaa.spec("spec.yaml").run().output

input/clinic.csv

input/home.csv

expected/vs.csv

Your review

Mapping spec

yamaa code

R

Python