# Specimen plates

The plate studio regenerates finite addressed geometry as standalone SVG. It is adapted from the useful deterministic plate idea and semilinear recursion in Bernat Espigule's **Here Be Dragons 1.1.0**; the present interface, restrained scientific plate layout and metadata contract are new. No interval certification code, unverified tent-tile classification or topology badges have been imported.

Serve the parent atlas with a static HTTP server and open `/4D/plates/`. No build, CDN, external font, account or analytics is needed. The studio is linked from the public explorer.

## Geometry

The kernel composes `outer ∘ inner`; the leftmost address symbol is the outermost map. It handles DD, DO and OO with a conjugation bit. Every one of the `2^N` word images of zero is rendered. The colour is determined by the outermost map. Two compact vector paths carry the geometry, following the v1.1 approach, with SVG coordinates rounded to 0.001 SVG units. The full symbolic addresses can be reconstructed in binary lexicographic order from the stored depth, family and parameters.

The scale can be common to all panels, enabling direct spatial comparison, or individually fitted. Each panel is centred on its finite coordinate bounding box; common scale does not mean common origin. All input coordinates, computed multipliers, orientation bits (through the family), render depth, counts, scales and explorer hashes are stored in SVG metadata and exportable as JSON.

The tail estimate `qMax^N/(1-qMax)` is the geometric truncation bound evaluated numerically. It does **not** enclose floating arithmetic error or rounding introduced when serializing SVG coordinates. No filled cylinders, measures, connectedness tests, enclosure certificates, limiting contact relations or topology classification are asserted by this renderer.

## Terminology

- **Equal contraction ratios:** `|lambdaMinus| = |lambdaPlus|`.
- **Homogeneous DD:** `lambdaMinus = lambdaPlus`.
- **Finite address centres:** the displayed values `f_u(0)`.
- **Direct / reversing:** the two possible orientation types of a planar similarity.

The DD presets are coordinate illustrations from the historical atlas. Classical labels identify those coordinates and do not claim a new theorem. The orientation comparison deliberately assigns no borrowed dragon names to DO and OO supports.

## Exports

SVG is resolution-independent vector geometry. Increasing the SVG display size does not increase sampling depth: adjust depth separately. Exported specimen links are relative to the adjacent explorer and work when served with the directory tree; the parameter JSON retains the complete state hash for use elsewhere. The full-precision state hash omits a landmark ID to avoid attaching a catalogue claim to a nearby free parameter.

## Verification

Run `node --test 4D/plates/tests/plates.test.mjs` from the atlas root. The suite independently checks nested semilinear applications for all three orientation components, first-symbol preservation, complete addresses, validity guards, deterministic SVG, metadata/state restoration, scaling, SVG escaping and explicit claim limits.

Browser interaction is covered by the shared `../qa/browser.mjs` acceptance harness: desktop and narrow viewports, SVG downloads, deep links and finite-depth rendering.