feat(highcharts): implement ecdf-basic

[github-actions]

Implementation: ecdf-basic - python/highcharts

Implements the python/highcharts version of ecdf-basic.

File: plots/ecdf-basic/implementations/python/highcharts.py

Parent Issue: #976

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

Light render (plot-light.png): The plot is rendered on a warm off-white background (≈#FAF8F1), correctly matching the light theme specification. The title reads "API Response Times · ecdf-basic · highcharts · anyplot.ai" in bold dark text, clearly readable. A smaller subtitle below the title — "Empirical cumulative distribution across 220 sampled requests" — adds context and is readable. The X-axis is labeled "Response Time (ms)" and the Y-axis is labeled "Cumulative Proportion" (rotated), both in dark text with appropriate sizing. Tick labels (0, 0.2, 0.4, 0.6, 0.8, 1 on Y; 0–600ms on X) are visible, though the "1" tick at the top Y-axis edge is slightly crowded against the top plot border. The ECDF step function is rendered in brand green (#009E73), rising steeply between 0–200ms (where most API responses concentrate) then flattening toward 1.0 for the remaining tail. Subtle horizontal grid lines aid percentile reading. All four chart spines form a full box frame. All text is clearly readable against the light background — legibility verdict: PASS.

Dark render (plot-dark.png): The same chart appears on a near-black background (≈#1A1A17), correctly matching the dark theme specification. The title, subtitle, axis labels, and tick labels all flip to light-colored text, clearly readable against the dark surface — no dark-on-dark failures detected. The ECDF data line remains the identical #009E73 brand green (data color is unchanged between themes, as required). Subtle lighter grid lines are visible on the dark surface. The box frame and layout structure are identical to the light render. Both themes show the same data shape — steep rise through 0–200ms response times then a long plateau approaching 1.0. All text is clearly readable against the dark background — legibility verdict: PASS.

Both renders confirm theme adaptation is correctly implemented. Data colors are identical across both themes; only chrome (background, text, grid) flips.

Score: 86/100

Category	Score	Max
Visual Quality	28	30
Design Excellence	11	20
Spec Compliance	15	15
Data Quality	15	15
Code Quality	10	10
Library Mastery	7	10
Total	86	100

Visual Quality (28/30)

• VQ-01: Text Legibility (7/8) — Title, subtitle, axis labels, and tick labels are all explicitly sized and clearly readable in both themes; slight deduction for the y=1 tick being tight against the top border.
• VQ-02: No Overlap (6/6) — No overlapping text or chart elements.
• VQ-03: Element Visibility (6/6) — ECDF step line is perfectly visible and appropriately weighted in both renders.
• VQ-04: Color Accessibility (2/2) — Single series in #009E73 (Okabe-Ito position 1), CVD-safe with strong contrast.
• VQ-05: Layout & Canvas (3/4) — Good canvas utilization overall; minor deduction for the Y-axis "1" tick crowding the top edge (top margin slightly too tight).
• VQ-06: Axis Labels & Title (2/2) — "Response Time (ms)" includes units; "Cumulative Proportion" is descriptive. Title is informative.
• VQ-07: Palette Compliance (2/2) — First (only) series is #009E73 ✓; light background is warm off-white ✓; dark background is near-black ✓; all chrome elements adapt correctly between themes ✓.

Design Excellence (11/20)

• DE-01: Aesthetic Sophistication (5/8) — Above default: uses the brand green, adds an informative subtitle, clean step function rendering. Below 6/8 because the full box frame (all 4 spines) deviates from the style guide's L-shaped frame standard, and no distinctive design choices beyond color.
• DE-02: Visual Refinement (3/6) — Subtle, appropriate grid lines; however, all four spines are retained (style guide requires removing top and right spines for an L-shaped or spine-free frame). No other refinement issues.
• DE-03: Data Storytelling (3/6) — The subtitle "Empirical cumulative distribution across 220 sampled requests" adds good context. Real-world API response time scenario is compelling. But there are no percentile reference lines (p50, p90, p95) or annotations to guide the reader to key insights from the distribution.

Spec Compliance (15/15)

• SC-01: Plot Type (5/5) — Correct ECDF step function chart; step rises by 1/n at each data point.
• SC-02: Required Features (4/4) — Step function ✓; Y-axis 0 to 1 ✓; grid lines for reading percentiles ✓; distinct line style ✓.
• SC-03: Data Mapping (3/3) — Values on X (Response Time ms), cumulative proportion on Y (0–1). Full data range visible.
• SC-04: Title & Legend (3/3) — Title: "API Response Times · ecdf-basic · highcharts · anyplot.ai" includes spec-id and library ✓. No legend (single series — appropriate).

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6) — Full ECDF from 0 to 1 displayed; step function shape clearly shows distribution concentration and long tail; all 220 data points represented.
• DQ-02: Realistic Context (5/5) — API response time data for a web service is a real-world, neutral, technically credible scenario.
• DQ-03: Appropriate Scale (4/4) — Response times 0–620ms for 220 sampled requests is highly realistic for a web API endpoint.

Code Quality (10/10)

• CQ-01: KISS Structure (3/3) — Flat script structure: imports → data generation → chart configuration → export.
• CQ-02: Reproducibility (2/2) — Random seed set for deterministic data generation.
• CQ-03: Clean Imports (2/2) — Imports limited to what is used (tempfile, time, urllib, pathlib, numpy, highcharts_core, selenium).
• CQ-04: Code Elegance (2/2) — Clean step data construction; no fake UI elements; no over-engineering.
• CQ-05: Output & API (1/1) — Outputs confirmed: plot-light.png, plot-dark.png, plot-light.html, plot-dark.html — all correctly themed and named.

Library Mastery (7/10)

• LM-01: Idiomatic Usage (4/5) — Correctly uses Chart(container="container"), HighchartsOptions, LineSeries, inline JS download for headless Chrome, and Selenium screenshot. Above the default pattern.
• LM-02: Distinctive Features (3/5) — Uses Highcharts-specific step: 'left' parameter for the step function, and generates interactive HTML with hover tooltips as a Highcharts-native capability. Does not reach 5/5 as no advanced Highcharts features (custom tooltip formatters, responsive rules, drilldown) are leveraged.

Score Caps Applied

• None — no caps triggered (DE-01=5>2, all other cap conditions clear).

Strengths

• Perfect spec compliance: correct ECDF step function with Y-axis 0–1, grid lines, and distinct line style (15/15).
• Excellent data quality: real-world API response time scenario with 220 samples and realistic 0–620ms range (15/15).
• Correct theme adaptation: both renders have proper backgrounds (#FAF8F1 / #1A1A17), adaptive chrome, and identical #009E73 data color.
• Informative subtitle adds context without cluttering the chart.
• Correct output artifacts: themed PNG and HTML files generated for both light and dark modes.

Weaknesses

• All four spines form a box frame — style guide requires removing top and right spines (L-shaped frame). This is the clearest visual refinement issue.
• No percentile reference lines (p50, p90, p95) or annotations to guide the reader toward key distribution insights — the ECDF shape is displayed but not interpreted.
• Top margin is slightly tight — the Y-axis "1" tick label crowds the top border; increase marginTop or spacingTop.

Issues Found

1. DE-02 LOW: Full box frame retained; style guide requires removing top and right spines.
   • Fix: Set chart.options.chart with margin adjustments and configure the plot area to hide top/right axis lines; or use x_axis.line_color and y_axis.line_color set to 'transparent' for the axes that should not show, effectively removing top/right spine equivalents.
2. DE-03 LOW: No percentile markers to guide interpretation of the ECDF.
   • Fix: Add horizontal reference lines at y=0.5 (p50), y=0.9 (p90), and y=0.95 (p95) using Highcharts plot_lines on the Y-axis; label each line with its percentile value and corresponding x-intercept read from the ECDF.
3. VQ-05 MINOR: Y-axis top crowding — "1" tick at the upper edge.
   • Fix: Increase spacingTop or marginTop in chart.options.chart by 20–40px.

AI Feedback for Next Attempt

Remove top and right axis lines to achieve the L-shaped frame (set lineWidth: 0 or lineColor: 'transparent' on the top/right axis equivalents). Add Highcharts plotLines on the Y-axis for p50, p90, and p95 percentile markers — compute the x-intercepts from the sorted ECDF data and label each line with both the percentile name and its x value (e.g., "p90 = 312 ms") using label: {text: ..., align: 'left'}. Increase top spacing to prevent the y=1 tick from crowding the chart border.

Verdict: REJECTED