Equipment tags found exactly once in each drawing are matched (a tag
found twice - a plan copy, a legend - is reported ambiguous and takes no
part; two plan copies resolve to the cluster that matches the most
tags). For every pair of matched tags at least min_pair_mm apart on the
reference, the ratio of their distances is taken in millimetres by each
drawing's inferred unit; the median, the quartiles, the share within
+/-10 % of the median, the same per room of the reference, and the
verdict: to_scale (>= 80 %, with its factor), schematic (<= 50 %),
partly, or insufficient under three matched tags.
server.py grows SECTION 26 to two tools with drawing_scale_check (core,
read-only, tagged analysis/query); alias record, inventory, README
release snapshot 243, frozen group sizes (analysis 14).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
A drawing somebody else made, read back as one report in which every
claim carries its evidence and a confidence; the drawing is never
modified.
- units.py: $INSUNITS against the unit the geometry implies (text
heights, wall thickness, door swings, labelled room areas, overall
size). The header is overruled only when the evidence outweighs it,
and then with a warning that quotes the numbers. Robust extents grow
from the quartile box of entity centres; what never joins is an
outlier, named by handle.
- clusters.py: separate bodies of model-space content by raster,
8-connectivity and box absorption - two copies of one plan are two
clusters.
- describe.py: layers with drawn length and the vocabulary's meaning
(name keyword, else the texts on the layer), equipment tags (one tag
lettered twice beside its symbol merged, repeats flagged ambiguous),
room labels in the wall-layer faces of engineering.arch.faces, text
languages by character class, blocks, layouts, the title block.
- server.py opens SECTION 26 (Understanding & QA) with
drawing_understand: core, read-only, tagged analysis/query. Alias
record, inventory, README release snapshot 242, frozen group sizes
(analysis 13).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
Track H's foundation, landed on main before its three groups branch.
- engineering/understand/snapshot.py: one bulk read of a drawing into frozen
WCS records (OCS translated through backends/ocs.py, text decoded, an
INSERT boxed by its block geometry without its attribute texts). A DXF is
read with ezdxf after the size check; the headless engine's document is
read under its own lock; the live engine exports the active document with
Document.Export(<tmp>/snap, "DXF", <set of all>) - never renamed, deleted
afterwards - and a DWG is opened read-only, exported and closed. Measured on
AutoCAD 2026: ".dxf" is refused with Invalid argument, the file lands as
snap.DXF, model space, paper space and unused block definitions all reach
it, and the selection set does not narrow a DXF export.
- engineering/understand/labels.py: %%c, \U+2205, the U+2300 sign, o-stroke
and MTEXT format runs all read as one diameter spelling; sizes are kept as
drawn and never equated; Cyrillic look-alike capitals fold into Latin tags;
panels, wiring callouts and electrical data (kW, phases, volts, N, VFD) in
EN / TR / RU / NL / DE. A power that is not written stays None.
- engineering/understand/vocab.py: layer classification with a confidence and
the deciding keyword, supply / return words, room labels and block kinds in
five languages. A CIP layer without a direction word is not guessed.
- MAX_DXF_BYTES defaults to 512 MB (a real layout was 188 MB); the refusal
names the size and the variable. New `office` extra (openpyxl), also in
`full`; uv.lock regenerated.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
