feat(bokeh): implement timeline-basic

[github-actions]

Implementation: timeline-basic - bokeh

Implements the bokeh version of timeline-basic.

File: plots/timeline-basic/implementations/bokeh.py

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

The plot displays a horizontal timeline visualization showing 10 software project milestones from January 2024 to October 2024. A central blue horizontal line serves as the timeline axis. Events are represented by colored circular markers (size ~35) positioned alternately above and below the axis with vertical connector lines. The 5 project phases are color-coded using Category10 palette: Planning (blue), Design (orange), Development (green), Testing (red), and Release (purple). Event labels appear above/below their respective markers. The title "timeline-basic · bokeh · pyplots.ai" is displayed in blue (#306998) at the top center. A legend titled "Phase" in the top-right shows all categories. The x-axis displays dates with slight rotation, labeled "Date". Background is light gray (#fafafa) with dashed vertical grid lines.

Quality Score: 91/100

Criteria Checklist

Visual Quality (36/40 pts)

• VQ-01: Text Legibility (9/10) - Title 32pt, axis labels 24pt, tick labels 18pt, event labels 18pt - all clearly readable, slightly below optimal for event labels
• VQ-02: No Overlap (8/8) - Alternating above/below positioning prevents text overlap excellently
• VQ-03: Element Visibility (8/8) - Markers size 35 with alpha 0.9, connector lines visible, well-adapted for 10 events
• VQ-04: Color Accessibility (4/5) - Category10 palette is generally colorblind-friendly, but red/green could be challenging for some
• VQ-05: Layout Balance (5/5) - Good use of canvas, timeline centered, balanced margins, legend well-positioned
• VQ-06: Axis Labels (1/2) - "Date" label present but no units (though dates are self-explanatory for timeline)
• VQ-07: Grid & Legend (1/2) - Grid is dashed with alpha 0.3 (good), legend well-styled but slightly far from data

Spec Compliance (25/25 pts)

• SC-01: Plot Type (8/8) - Correct timeline visualization with events along temporal axis
• SC-02: Data Mapping (5/5) - Date on x-axis, events as labeled markers, category for color-coding
• SC-03: Required Features (5/5) - Horizontal orientation, alternating labels, color-coding by category, clear date formatting
• SC-04: Data Range (3/3) - Full date range visible with padding
• SC-05: Legend Accuracy (2/2) - Legend accurately shows all 5 phases with correct colors
• SC-06: Title Format (2/2) - Correct format: "timeline-basic · bokeh · pyplots.ai"

Data Quality (18/20 pts)

• DQ-01: Feature Coverage (7/8) - Shows multiple phases, varying time gaps, 10 events - demonstrates timeline well but could show more varied spacing
• DQ-02: Realistic Context (7/7) - Software project milestones is an excellent, neutral, realistic scenario
• DQ-03: Appropriate Scale (4/5) - Dates span 9 months which is realistic for a software project, events well-distributed

Code Quality (9/10 pts)

• CQ-01: KISS Structure (3/3) - Clean linear flow: imports → data → figure → plot → style → save
• CQ-02: Reproducibility (2/3) - Data is deterministic (hardcoded dates), but no explicit seed for any random elements
• CQ-03: Clean Imports (2/2) - All imports are used (pandas, bokeh.io, bokeh.models, bokeh.palettes, bokeh.plotting)
• CQ-04: No Deprecated API (1/1) - Uses current Bokeh APIs
• CQ-05: Output Correct (1/1) - Saves as plot.png and plot.html

Library Features (3/5 pts)

• LF-01: Distinctive Features (3/5) - Uses ColumnDataSource, Label model, figure with datetime axis, legend configuration - good Bokeh usage but could leverage more interactive features or tooltips

Strengths

• Excellent alternating label positioning above/below axis prevents text overlap
• Clean category color-coding with proper legend showing all 5 project phases
• Good use of Bokeh's ColumnDataSource for categorical grouping in scatter plot
• Proper 4800x2700 sizing with appropriate font sizes for the canvas
• Realistic software project milestone scenario with logical progression
• Both PNG and HTML outputs generated for static and interactive viewing

Weaknesses

• Event label font size (18pt) could be slightly larger for better readability at full resolution
• Legend positioned far from data area in top-right corner
• Could benefit from Bokeh-specific features like HoverTool for interactivity

Verdict: APPROVED