feat(altair): implement violin-grouped-swarm

[github-actions]

Implementation: violin-grouped-swarm - altair

Implements the altair version of violin-grouped-swarm.

File: plots/violin-grouped-swarm/implementations/altair.py

Parent Issue: #3529

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

The plot displays a grouped violin plot with swarm overlay showing response times across three task types (Simple, Moderate, Complex) faceted horizontally. Each facet contains two violin shapes colored by expertise level: Novice in steel blue (#306998) and Expert in golden yellow (#FFD43B). Individual data points are overlaid as circles with slight horizontal jitter, matching their respective violin colors. The title "violin-grouped-swarm · altair · pyplots.ai" appears at the top. The y-axis shows "Response Time (s)" ranging from 0-13, and the x-axis labels each facet by Task Type. A legend on the right identifies the Expertise Level with appropriately sized symbols. Violins have 50% opacity allowing swarm points to show through. The data demonstrates expected patterns: novices have higher and more variable response times, with complexity increasing times for both groups.

Quality Score: 83/100

Criteria Checklist

Visual Quality (34/40 pts)

• VQ-01: Text Legibility (9/10) - Title and labels are clear and readable, font sizes appropriate
• VQ-02: No Overlap (8/8) - No overlapping text elements
• VQ-03: Element Visibility (6/8) - Swarm points visible but some appear detached from violins in Simple category
• VQ-04: Color Accessibility (4/5) - Blue/yellow distinguishable but not optimal for all colorblind types
• VQ-05: Layout Balance (4/5) - Good use of space, faceted layout works well
• VQ-06: Axis Labels (2/2) - "Response Time (s)" includes units
• VQ-07: Grid & Legend (1/2) - Legend placed well, but no visible grid lines

Spec Compliance (23/25 pts)

• SC-01: Plot Type (8/8) - Correct grouped violin with swarm overlay
• SC-02: Data Mapping (5/5) - Category on x-axis (faceted), group as color, value on y-axis
• SC-03: Required Features (4/5) - Violins have transparency, swarm points colored by group, but alignment could be better
• SC-04: Data Range (3/3) - All data visible within axis range
• SC-05: Legend Accuracy (1/2) - Legend labels correct but title could be more descriptive ("Expertise" vs "Expertise Level")
• SC-06: Title Format (2/2) - Correct format: {spec-id} · {library} · pyplots.ai

Data Quality (18/20 pts)

• DQ-01: Feature Coverage (7/8) - Shows distribution differences, variance differences, but could show more outlier variation
• DQ-02: Realistic Context (7/7) - Response times across task complexity and expertise is a realistic scenario
• DQ-03: Appropriate Scale (4/5) - Values realistic (0.5-12s), though some clipped values at bounds

Code Quality (10/10 pts)

• CQ-01: KISS Structure (3/3) - Linear structure: imports → data → plot → save
• CQ-02: Reproducibility (3/3) - np.random.seed(42) set
• CQ-03: Clean Imports (2/2) - Only necessary imports used
• CQ-04: No Deprecated API (1/1) - Uses current Altair API
• CQ-05: Output Correct (1/1) - Saves as plot.png and plot.html

Library Features (5/5 pts)

• LF-01: Uses distinctive library features (5/5) - Excellent use of Altair's declarative grammar: transform_density, transform_calculate for jitter, faceting, layer composition

Strengths

• Excellent use of Altair's declarative API with transform_density for violin shapes
• Good implementation of jitter using transform_calculate for swarm effect
• Clean faceted layout separates task types clearly
• Appropriate transparency on violins allows swarm points to remain visible
• Realistic data scenario with meaningful patterns (experts faster, less variance)
• Proper color-coding with swarm points matching violin colors

Weaknesses

• Swarm points appear slightly misaligned with violin positions in some facets (particularly "Simple" Novice)
• Missing subtle grid lines would improve readability
• Legend title says "Expertise Level" but data column is "Expertise" - minor inconsistency

Verdict: REJECTED

[github-actions]

🔧 Repair Attempt 1/3

Applied fixes based on AI review feedback.

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

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🤖 impl-repair

[claude]

AI Review - Attempt 2/3

Image Description

The plot displays a grouped violin plot with swarm overlay for response times across three task types: Simple, Moderate, and Complex. The visualization uses faceting with three panels arranged horizontally. Blue violins and points represent "Novice" expertise level while yellow represents "Expert". Each violin shows the distribution shape with 50% opacity, and swarm points are overlaid at 85% opacity with size 120. The title "violin-grouped-swarm · altair · pyplots.ai" appears at the top in large text. The y-axis shows "Response Time (s)" ranging from 0 to 13, with a subtle grid. The legend is positioned on the right showing "Expertise Level" with colored circles for Novice (blue) and Expert (yellow). The data clearly demonstrates that experts (yellow) have faster response times with tighter distributions compared to novices (blue), and complexity increases response times for both groups.

Quality Score: 90/100

Criteria Checklist

Visual Quality (35/40 pts)

• VQ-01: Text Legibility (10/10) - Title at fontSize=32, axis labels at 24, tick labels at 20, all perfectly readable
• VQ-02: No Overlap (8/8) - No overlapping text elements, facet labels well spaced
• VQ-03: Element Visibility (6/8) - Swarm points visible (size=120, opacity=0.85), violins at opacity=0.5. Minor issue: some points extend beyond violin boundaries
• VQ-04: Color Accessibility (5/5) - Blue (#306998) and yellow (#FFD43B) are colorblind-safe, high contrast
• VQ-05: Layout Balance (3/5) - Good use of faceting, though some wasted space on left/right edges. Plot fills reasonable portion of canvas
• VQ-06: Axis Labels (2/2) - "Response Time (s)" with units, "Task Type" as facet header
• VQ-07: Grid & Legend (1/2) - Grid at opacity=0.3 is subtle, legend well placed. Minor: legend title mismatch with column name

Spec Compliance (23/25 pts)

• SC-01: Plot Type (8/8) - Correct grouped violin plot with swarm overlay
• SC-02: Data Mapping (5/5) - Categories on x-axis, values on y-axis, groups as color
• SC-03: Required Features (4/5) - Has violins, swarm points, grouping. Minor: points not perfectly dodged to align within violins
• SC-04: Data Range (3/3) - Y-axis 0-13 shows all data appropriately
• SC-05: Legend Accuracy (1/2) - Legend shows correct colors but title says "Expertise Level" vs column "Expertise"
• SC-06: Title Format (2/2) - Correctly formatted as "violin-grouped-swarm · altair · pyplots.ai"

Data Quality (19/20 pts)

• DQ-01: Feature Coverage (8/8) - Shows varied distributions: different widths, positions, and spreads across groups
• DQ-02: Realistic Context (6/7) - Response times for task complexity is plausible. Good scenario for expertise comparison
• DQ-03: Appropriate Scale (5/5) - Response times 0.5-12 seconds are realistic for cognitive tasks

Code Quality (10/10 pts)

• CQ-01: KISS Structure (3/3) - Clean sequential structure: imports → data → base chart → layers → save
• CQ-02: Reproducibility (3/3) - np.random.seed(42) set at start
• CQ-03: Clean Imports (2/2) - Only altair, numpy, pandas used
• CQ-04: No Deprecated API (1/1) - Uses current Altair 6.0 API
• 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 transform_density, faceting, jitter transform. Good use of Altair's declarative approach and layering, but jitter implementation is manual rather than using built-in swarm functionality

Strengths

• Excellent use of Altair's declarative grammar with transform_density and faceting
• Clean layered composition of violin and swarm elements
• Good color scheme with colorblind-safe palette
• Appropriate transparency allowing both layers to be visible
• Clear visual differentiation between expertise levels
• Proper title format and axis labeling with units

Weaknesses

• Swarm points are positioned using random jitter rather than true swarm algorithm, causing some points to extend beyond violin boundaries
• Legend title inconsistency ("Expertise Level" in display vs "Expertise" column name)

Verdict: APPROVED