feat(highcharts): implement quiver-basic

[github-actions]

Implementation: quiver-basic - javascript/highcharts

Implements the javascript/highcharts version of quiver-basic.

File: plots/quiver-basic/implementations/javascript/highcharts.js

Parent Issue: #1014

---

🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

Light render (plot-light.png): Warm off-white background (~#FAF8F1). Bold dark title "quiver-basic · javascript · highcharts · anyplot.ai" and a secondary-weight subtitle are both clearly readable. Axis titles "x"/"y" and tick labels (-7..7 on x, -8..8 on y) read fine against the light background; faint horizontal gridlines only. 144 arrows (12×12 grid) form a spiral/rotational flow pattern — short brand-green arrows near the center growing into longer blue arrows toward the edges, correctly encoding vector magnitude via the imprint_seq gradient. All text is readable — no light-on-light issues.

Dark render (plot-dark.png): Warm near-black background (~#1A1A17). Title, subtitle, axis titles, tick labels, and gridlines all flip to light/soft tones and stay fully legible — no dark-on-dark failures found anywhere. The arrow field itself is color-identical to the light render (same green→blue magnitude gradient, same positions/lengths); only the chrome flipped, as expected.

Both renders pass legibility.

Score: 83/100

Category	Score	Max
Visual Quality	27	30
Design Excellence	13	20
Spec Compliance	15	15
Data Quality	13	15
Code Quality	9	10
Library Mastery	6	10
Total	83	100

Visual Quality (27/30)

• VQ-01: Text Legibility (8/8)
• VQ-02: No Overlap (6/6)
• VQ-03: Element Visibility (6/6)
• VQ-04: Color Accessibility (2/2)
• VQ-05: Layout & Canvas (3/4) - Square canvas suits the grid, but xAxis/yAxis default startOnTick/endOnTick auto-extend independently despite identical explicit min/max, so y reaches 8 while x reaches 7 — mildly unbalanced whitespace top/bottom vs left/right
• VQ-06: Axis Labels & Title (0/2) - Axis titles are the literal generic labels "x" and "y"
• VQ-07: Palette Compliance (2/2)

Design Excellence (13/20)

• DE-01: Aesthetic Sophistication (5/8) - Magnitude-driven color gradient is a nice touch, but composition stays fairly utilitarian
• DE-02: Visual Refinement (4/6) - Subtle gridlines and generous whitespace, but not maximally polished
• DE-03: Data Storytelling (4/6) - Spiral pattern + magnitude gradient make the flow structure immediately readable

Spec Compliance (15/15)

• SC-01: Plot Type (5/5)
• SC-02: Required Features (4/4)
• SC-03: Data Mapping (3/3)
• SC-04: Title & Legend (3/3)

Data Quality (13/15)

• DQ-01: Feature Coverage (6/6)
• DQ-02: Realistic Context (3/5) - Uses the spec's own suggested "simple mathematical function" (spiral rotation) rather than a named real-world phenomenon; plausible but generic/abstract
• DQ-03: Appropriate Scale (4/4)

Code Quality (9/10)

• CQ-01: KISS Structure (2/3) - Small helper functions and the chart.events.render callback are necessary given Highcharts' lack of a native vector-field series
• CQ-02: Reproducibility (2/2)
• CQ-03: Clean Imports (2/2)
• CQ-04: Code Elegance (2/2)
• CQ-05: Output & API (1/1)

Library Mastery (6/10)

• LM-01: Idiomatic Usage (4/5) - No native quiver series exists; using chart.renderer + axis.toPixels() inside chart.events.render is the documented idiomatic pattern for custom overlays
• LM-02: Distinctive Features (2/5) - Uses Highcharts' renderer/axis API, but the same effect is achievable with comparable effort in other SVG-based chart libraries

Score Caps Applied

• None

Strengths

• Correctly uses imprint_seq (brand green → blue) as a continuous colormap for vector magnitude, identical between light and dark renders
• Creative, well-justified workaround for Highcharts' lack of a native quiver/vector-field series: custom SVG arrows drawn via chart.renderer + axis.toPixels() inside chart.events.render, clearly commented
• Arrow lengths are scaled (ARROW_SCALE) so the longest vector spans ~90% of grid spacing, preventing overlap regardless of field strength
• Theme-adaptive chrome is fully correct across both renders
• Deterministic spiral flow field (12×12 = 144 arrows) clearly shows both rotational direction and magnitude growth toward the edges

Weaknesses

• Axis titles are the literal single letters "x" and "y" — scored as generic per VQ-06; consider a slightly more descriptive label such as "Grid X" / "Grid Y"
• xAxis and yAxis are given identical explicit min/max in code, but Highcharts' default startOnTick/endOnTick auto-extends each axis independently based on its pixel length, so the rendered y-axis reaches 8 while x only reaches 7 — set startOnTick: false, endOnTick: false (or a matching explicit tickInterval) on both axes so the rendered ranges stay symmetric
• The data scenario is a generic mathematical spiral/rotation field rather than a named real-world phenomenon — acceptable since the spec suggests this, but scores lower on Realistic Context
• No colorbar/scale legend quantifies the magnitude-to-color mapping — a viewer can only compare arrows relatively
• The custom chart.renderer overlay technique, while idiomatic to Highcharts, doesn't showcase a feature that's hard to replicate in other SVG-based chart libraries

Issues Found

1. VQ-06 LOW: Axis titles are generic single letters "x"/"y"
   • Fix: Use a slightly more descriptive axis title, e.g. "Grid X" / "Grid Y" or similar, even though this is an abstract coordinate space
2. VQ-05 MEDIUM: Asymmetric rendered axis range despite identical explicit min/max
   • Fix: Set startOnTick: false, endOnTick: false on both xAxis and yAxis (or specify a matching explicit tickInterval) so Highcharts doesn't independently pad each axis to different "nice" tick bounds
3. LM-02 LOW: Custom-render technique is somewhat generic across SVG-based libraries
   • Fix: Consider a Highcharts-specific touch (e.g. Highcharts.SVGRenderer symbol definitions, or leveraging chart.renderer.symbol for reusable arrowhead markers) to make the implementation more distinctly Highcharts

AI Feedback for Next Attempt

Fix the axis-range asymmetry by disabling startOnTick/endOnTick (or setting explicit matching tickInterval) on both axes so the square canvas has balanced whitespace on all sides. Give the axis titles slightly more descriptive text than bare "x"/"y". Optionally add a small magnitude colorbar/scale reference to strengthen data storytelling, and consider naming the scenario after a concrete real-world flow (e.g. "idealized vortex/eddy flow") for a stronger Realistic Context score.

Verdict: REJECTED

[github-actions]

🔧 Repair Attempt 1/4

Applied fixes based on AI review feedback.

Status: Repair completed, re-triggering review...

---

🤖 impl-repair

[claude]

AI Review - Attempt 2/3

Image Description

Light render (plot-light.png): Warm off-white background with a bold dark title "quiver-basic · javascript · highcharts · anyplot.ai" and a gray subtitle describing the vortex/eddy field. "Grid X"/"Grid Y" axis titles and -7..7 tick labels are dark and crisp. 144 arrows (12x12 grid) form a clear counter-clockwise vortex with slight outward drift — arrows are near-invisible at the core (magnitude ~0) and grow toward the outer ring, colored from teal-green to blue via imprint_seq to encode magnitude. A magnitude colorbar sits in the right margin labeled "‖v‖" with "8.7" (max) and "0" (min). All text is clearly readable against the light background — no light-on-light issues found.

Dark render (plot-dark.png): Same layout on a warm near-black background — title and subtitle now render in near-white/light-gray, axis titles/tick labels/colorbar labels in light gray, all clearly legible. The vortex arrows use the identical teal-green-to-blue color range as the light render — only chrome (background, text, grid) flipped. No dark-on-dark failures: every text element is clearly visible against the near-black surface.

Both paragraphs are required. A review that only describes one render is invalid.

Score: 92/100

Category	Score	Max
Visual Quality	29	30
Design Excellence	15	20
Spec Compliance	15	15
Data Quality	15	15
Code Quality	9	10
Library Mastery	10	10
Total	92	100

Visual Quality (29/30)

• VQ-01: Text Legibility (8/8)
• VQ-02: No Overlap (6/6)
• VQ-03: Element Visibility (6/6)
• VQ-04: Color Accessibility (2/2)
• VQ-05: Layout & Canvas (4/4)
• VQ-06: Axis Labels & Title (1/2) - "Grid X"/"Grid Y" are descriptive but generic, no units
• VQ-07: Palette Compliance (2/2)

Design Excellence (15/20)

• DE-01: Aesthetic Sophistication (6/8) - Fully custom vector-field rendering with rotated arrowhead symbol, clearly above defaults
• DE-02: Visual Refinement (5/6) - Clean whitespace, subtle grid, no chart junk
• DE-03: Data Storytelling (4/6) - Color+magnitude encoding creates hierarchy but no explicit annotation/callout

Spec Compliance (15/15)

• SC-01: Plot Type (5/5)
• SC-02: Required Features (4/4)
• SC-03: Data Mapping (3/3)
• SC-04: Title & Legend (3/3)

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6)
• DQ-02: Realistic Context (5/5)
• DQ-03: Appropriate Scale (4/4)

Code Quality (9/10)

• CQ-01: KISS Structure (2/3) - a couple of small helper arrow functions (hexToRgb, colorForMagnitude)
• CQ-02: Reproducibility (2/2)
• CQ-03: Clean Imports (2/2)
• CQ-04: Code Elegance (2/2)
• CQ-05: Output & API (1/1)

Library Mastery (10/10)

• LM-01: Idiomatic Usage (5/5)
• LM-02: Distinctive Features (5/5) - Custom SVGRenderer symbol registration + rotation transform for oriented arrowheads

Score Caps Applied

• None

Strengths

• Registers a custom Highcharts SVGRenderer symbol (quiverArrowhead) and rotates it per-vector via rotation/rotationOriginX/Y — a genuinely idiomatic, library-distinctive technique for oriented markers
• Magnitude-to-color continuous encoding correctly uses imprint_seq (brand green → blue), identical across light/dark renders
• Arrow length auto-scaled so the longest vector spans ~90% of grid spacing, guaranteeing no overlap regardless of field strength
• Deterministic vortex/eddy formula gives full feature coverage: rotation plus outward drift, near-zero core rising to a clear maximum at the edges
• Hand-drawn magnitude colorbar cleanly integrated into the reserved right margin with theme-adaptive ink colors

Weaknesses

• X-axis shows no vertical gridlines while the Y-axis shows horizontal ones — add matching xAxis grid rendering for a balanced, symmetric grid
• Axis titles "Grid X"/"Grid Y" are fairly generic — a slightly more descriptive label would help, even though no physical units apply to this idealized field
• The magnitude colorbar only labels the two endpoints (0 and 8.7) — an intermediate tick value would make the mapping easier to read at a glance

Issues Found

1. VQ-06 LOW: Axis titles lack units/specificity
   • Fix: Consider a more descriptive axis title if it improves clarity without inventing false units
2. DE-03 MODERATE: No explicit annotation/callout beyond color encoding
   • Fix: Optional — not required per spec, current color-hierarchy is sufficient for a good score

AI Feedback for Next Attempt

This is a strong, technically accomplished implementation — no changes required to pass. If revisiting, consider adding vertical gridlines to match the horizontal ones and an intermediate tick on the magnitude colorbar for polish.

Verdict: APPROVED