Reads a user-supplied twin-relations sidecar table into a data frame for
checkTwinRelations. The expected form is
id1, id2, code, with a header row (see
checkTwinRelations for the accepted code values).
Excel (.xls/.xlsx) and delimited text (.csv/
.txt) files are both accepted, mirroring
readKinshipOverrides – the closest existing precedent for
a validated, pairwise sidecar upload (issue #137 D1/D5,
docs/planning/issue137-twin-zygosity-pedigree-diagram-plan.md).
Value
A data frame of the rows read from fileName (typically with
columns id1, id2, and code). Validate it with
checkTwinRelations before use.
Details
This reader does not validate structure or domain – that is
checkTwinRelations's job.
Examples
if (FALSE) { # \dontrun{
twinRelations <- readTwinRelations(fileName = "twin_relations.csv")
twinRelations <- checkTwinRelations(ped, twinRelations)
} # }
