feat(highcharts): implement line-stepwise

[github-actions]

Implementation: line-stepwise - highcharts

Implements the highcharts version of line-stepwise.

File: plots/line-stepwise/implementations/highcharts.py

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

The plot displays a step line chart showing server response time over a 24-hour monitoring period. The chart uses Python blue (#306998) for the line and markers. The title "line-stepwise · highcharts · pyplots.ai" appears at the top with a subtitle "Server Response Time (24-Hour Monitoring)". The X-axis shows "Hour of Day" with time labels from 00:00 to 22:00 in 2-hour intervals. The Y-axis shows "Response Time (ms)" ranging from 40 to 100. The step pattern is clearly visible with horizontal segments showing value persistence and vertical segments showing instantaneous changes. Data points are marked with blue circles. The legend "Response Time" appears in the top-right corner. The chart shows realistic server load patterns: low response times (~48-54ms) during night hours (00:00-06:00), increased times during morning (~72-80ms at 06:00-09:00), lunch peak (~80-82ms at 12:00-14:00), evening peak reaching ~91ms around 17:00-18:00, then declining to ~50-59ms in late evening.

Quality Score: 91/100

Criteria Checklist

Visual Quality (36/40 pts)

• VQ-01: Text Legibility (9/10) - Title, axis labels, and tick marks are all readable. Font sizes are appropriate for the 4800x2700 canvas.
• VQ-02: No Overlap (8/8) - No overlapping text elements, X-axis labels spaced well with 2-hour intervals.
• VQ-03: Element Visibility (7/8) - Step lines and markers are clearly visible. Line width of 6 and marker radius of 12 work well.
• VQ-04: Color Accessibility (5/5) - Single color scheme (Python blue) is colorblind-safe.
• VQ-05: Layout Balance (4/5) - Good use of canvas space, though slight excess margin at top.
• VQ-06: Axis Labels (2/2) - Both axes have descriptive labels with units: "Hour of Day" and "Response Time (ms)".
• VQ-07: Grid & Legend (1/2) - Grid is subtle and appropriate. Legend placement is good but could be slightly larger.

Spec Compliance (25/25 pts)

• SC-01: Plot Type (8/8) - Correct step line chart with horizontal-then-vertical transitions using step: "left".
• SC-02: Data Mapping (5/5) - X shows time (hours), Y shows response time values correctly.
• SC-03: Required Features (5/5) - Step alignment implemented, clear distinction from smooth lines, horizontal segments show persistence.
• SC-04: Data Range (3/3) - Y-axis range (40-100) shows all data points appropriately.
• SC-05: Legend Accuracy (2/2) - Legend correctly labels the series as "Response Time".
• SC-06: Title Format (2/2) - Uses exact format line-stepwise · highcharts · pyplots.ai.

Data Quality (18/20 pts)

• DQ-01: Feature Coverage (7/8) - Shows step behavior well with discrete changes, varying step heights, and different patterns throughout the day. Could show more dramatic steps.
• DQ-02: Realistic Context (7/7) - Server response time monitoring is an excellent real-world use case for step plots, showing discrete sampling.
• DQ-03: Appropriate Scale (4/5) - Response times of 45-91ms are realistic for server monitoring, though the range could be slightly wider to show more variation.

Code Quality (9/10 pts)

• CQ-01: KISS Structure (3/3) - Follows imports → data → plot → save pattern, no functions/classes.
• CQ-02: Reproducibility (3/3) - Uses np.random.seed(42) for deterministic data.
• CQ-03: Clean Imports (2/2) - All imports are used (numpy, highcharts, selenium, etc.).
• CQ-04: No Deprecated API (1/1) - Uses current Highcharts API.
• CQ-05: Output Correct (0/1) - Note: Image appears to be 4800x2561 instead of 4800x2700, slight dimension mismatch.

Library Features (3/5 pts)

• LF-01: Uses distinctive library features (3/5) - Uses Highcharts step: "left" feature correctly. Also saves interactive HTML version. Could utilize more Highcharts-specific features like tooltips or animations.

Strengths

• Excellent implementation of step line using Highcharts' native step: "left" option
• Realistic and relevant data scenario (server response time monitoring)
• Clear step pattern showing discrete value changes throughout the day
• Proper title format following spec requirements
• Good use of subtitle for additional context
• Clean KISS code structure with reproducible seed
• Saves both PNG and interactive HTML output

Weaknesses

• Image dimensions slightly off (2561 vs 2700 height)
• Legend could be slightly larger for better visibility at high resolution
• Could utilize more Highcharts-specific interactive features like custom tooltips

Verdict: APPROVED