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SimurgArray/docs/known_unknowns.md
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kemal a7a235beb5 P1 validated on 1000 Genomes Omni2.5 (2141 vendor GTCs + IDATs)
All 2141 vendor-written GTC v3 files match BeadArrayFiles field by field
and re-encode byte-identically; all IDAT pairs parse; the 2.45M-locus BPM,
dbv-7 EGT and CSV manifest agree with BeadArrayFiles and each other.
Run on a self-destructing AWS spot instance (42 min, ~$0.20).
2026-09-27 20:22:35 +01:00

2.6 KiB

Known unknowns and findings log

Plan §20 lists the open questions; this file records what the implementation has learned. Newest first.

ID Date Topic Finding Status
K-008 2026-09-27 Vendor GTC layout 2141 vendor GTC v3 files (AutoCall 1.6.2.2) re-encode byte-identically with the canonical v3 order, so the writer reproduces the vendor layout (no padding or reordering). resolved
K-007 2026-09-27 Demo data The "GDA v1 Demo 36" download is a GenomeStudio project (.bsc + Data/*.bin), not IDATs. The GSA v4 PGx demo (idats_Demo_36.zip) is used as the P0 IDAT fixture instead. Bioconductor hapmap370k is no longer in the current release. resolved (plan §17 updated)
K-006 2026-09-27 Sample sheet Recognised input columns (Sample_ID, Sample_Name, …) collide case-insensitively with output columns sample_id/sample_name (IN-005). Recognised columns are exempt from the reserved-name check and are passed through verbatim. decision, revisit in P4 (OUT-060 pass-through)
K-005 2026-09-27 Sample sheet Illumina's GSA v4 template sheet has an empty Sample_Name column → E_SHEET_NAME_EMPTY (IN-010 behaviour as specified). as specified
K-004 2026-09-27 GTC scanner data PMT gains are 4 bytes read as int32 by BeadArrayFiles and written as float by gtc2vcf. We keep the raw 4 bytes (byte-exact round-trip) and expose the int32 view. resolved
K-003 2026-09-27 Assay type from sequences gtc2vcf's rule for inferring Infinium I colour from probe/source sequences (needed only for BPM locus entries < v6) agrees with the explicit BPM value for 99.71 % of GSA v4 Infinium I loci. The BPM is authoritative whenever it carries the assay type. documented; test threshold 99.5 %
K-002 2026-09-27 EGT data block (plan U3) GSA v4 and GDA v1 EGTs are data-block v9 with 15 extra floats per record; the first extra float is the intensity threshold (non-zero for 16 015 GDA loci). The reader tries candidate record sizes and accepts the one whose trailing cluster counts match. The Omni2.5 EGT is dbv 7 with 15 extra floats (structure confirmed); whether its first extra float is an intensity threshold (gtc2vcf) or unused (BeadArrayFiles) is still open. partly resolved
K-001 2026-09-27 IDAT MidBlock (plan U2) In GSA v4 (BeadChip 48x4), HumanCNV370 (2x12) and 450k (12x8) IDATs the MidBlock count equals N and the section is 4 bytes per entry (int32, as in illuminaio). gtc2vcf reads uint8 but never uses the values. We infer the element size from the section length. resolved for these chips + BeadChip 4x10 (Omni2.5, 2141 files)