history

EIS uses explicit plot-view actions

id: LK-20260721-eis-explicit-plot-views
date: 2026-07-21
sequence: 147
type: fix
compatibility: compatible
component: `labkit_EIS_app` | `1.5.1 -> 1.5.2`
scope: EIS Overlay

Context

EIS inferred an equal X/Y aspect ratio from specific Nyquist axis selections. That implicit choice could shrink the usable plotting area and make a redraw look unlike the user's current view.

Decision and rationale

Keep plot semantics in EIS, but use the App framework's viewport revision and data-fitting capability for view behavior. Equal data units are now an explicit one-time view reset rather than a rule tied to axis labels or a constraint on later zooming.

Changes

• Removed the EIS axis-label rule that automatically selected axis equal.
• Added Fit X/Y limits for independent data-fitted limits.
• Added Use equal X/Y scale for an explicit equal-data-unit view without changing the plot size allocated by the App layout.
• Kept ordinary zoom and wheel viewports under the framework-managed viewport preservation path.

User and data impact

Nyquist plots now begin with independent limits and a stable plot area. Equal scaling preserves the App layout's plot size. The new view buttons change only transient presentation; EIS sources, projects, calculations, and exports are unchanged.

Compatibility and migration

Existing saved projects remain valid. The selected axes and Log X/Y options keep their existing meaning; the equal-aspect choice is intentionally not saved with the project.

Validation

The EIS GUI workflow test covers both buttons, independent fitting, explicit equal aspect, and preservation of an ordinary manually chosen viewport.

Evidence

The renderer now uses labkit.app.plot.fitAxesToGraphics for both independent fits and equal-data-unit limits, and receives a new view revision only from an explicit view action.

Known limitations and follow-up

Automated GUI coverage cannot assess visual balance on every monitor and MATLAB release. Verify the Nyquist layout interactively before a release.