chore(pygal): update quality score 85 and review feedback for heatmap-cohort-retention

Author: github-actions[bot]

plots/heatmap-cohort-retention/implementations/pygal.py

@@ -1,7 +1,7 @@
-"""pyplots.ai
+""" pyplots.ai
 heatmap-cohort-retention: Cohort Retention Heatmap
-Library: pygal | Python 3.13
-Quality: pending | Created: 2026-03-16
+Library: pygal 3.1.0 | Python 3.14.3
+Quality: 85/100 | Created: 2026-03-16
 """
 
 import sys

plots/heatmap-cohort-retention/metadata/pygal.yaml

@@ -1,10 +1,7 @@
-# Per-library metadata for pygal implementation of heatmap-cohort-retention
-# Auto-generated by impl-generate.yml
-
 library: pygal
 specification_id: heatmap-cohort-retention
 created: '2026-03-16T20:46:42Z'
-updated: '2026-03-16T20:46:42Z'
+updated: '2026-03-16T20:50:54Z'
 generated_by: claude-opus-4-5-20251101
 workflow_run: 23165008448
 issue: 4570
@@ -13,7 +10,222 @@ library_version: 3.1.0
 preview_url: https://storage.googleapis.com/pyplots-images/plots/heatmap-cohort-retention/pygal/plot.png
 preview_thumb: https://storage.googleapis.com/pyplots-images/plots/heatmap-cohort-retention/pygal/plot_thumb.png
 preview_html: https://storage.googleapis.com/pyplots-images/plots/heatmap-cohort-retention/pygal/plot.html
-quality_score: null
+quality_score: 85
 review:
-  strengths: []
-  weaknesses: []
+  strengths:
+  - Excellent spec compliance — all required features implemented correctly including
+    triangular shape, cohort sizes, retention percentages in cells, and color bar
+  - Strong library mastery — properly subclasses pygal Graph class using idiomatic
+    _plot()/_compute() pattern with native SVG node creation and tooltip system
+  - Good color design — sequential green colormap with adaptive text contrast ensures
+    readability across all cells
+  - Realistic, neutral data — SaaS cohort retention with plausible values and natural
+    improvement trend
+  weaknesses:
+  - Design could be elevated to publication quality — the overall aesthetic is good
+    but not exceptional; needs more intentional visual hierarchy
+  - Data storytelling is limited — no visual emphasis on key insights like the retention
+    improvement trend across cohorts
+  - Custom class adds complexity that deviates from KISS structure
+  image_description: 'The plot displays a cohort retention heatmap with a triangular
+    shape. The title reads "heatmap-cohort-retention · pygal · pyplots.ai" centered
+    at the top. The y-axis is labeled "Signup Cohort" with monthly labels from Jan
+    2024 to Oct 2024, each showing cohort sizes (e.g., n=1,200). The x-axis header
+    reads "Months Since Signup" with columns Month 0 through Month 9. Cells are colored
+    using a sequential green colormap — dark green for 100% retention, progressively
+    lighter greens for lower values down to ~26%. Each cell displays its retention
+    percentage as text (white on dark backgrounds, dark on light backgrounds). The
+    triangular shape is correctly formed: Jan 2024 has 10 columns, each subsequent
+    cohort has one fewer. A vertical colorbar on the right side shows "Retention %"
+    with tick marks from 26% to 100%. White borders separate cells with rounded corners.'
+  criteria_checklist:
+    visual_quality:
+      score: 28
+      max: 30
+      items:
+      - id: VQ-01
+        name: Text Legibility
+        score: 7
+        max: 8
+        passed: true
+        comment: Font sizes explicitly set throughout (title 54px, headers ~42px,
+          row labels ~36px, cell values ~38px). Colorbar labels slightly small at
+          28px.
+      - id: VQ-02
+        name: No Overlap
+        score: 6
+        max: 6
+        passed: true
+        comment: No overlapping text. Clean cell gaps and spacing.
+      - id: VQ-03
+        name: Element Visibility
+        score: 6
+        max: 6
+        passed: true
+        comment: All cells clearly visible with good sizing, rounded corners, white
+          borders.
+      - id: VQ-04
+        name: Color Accessibility
+        score: 4
+        max: 4
+        passed: true
+        comment: Sequential green colormap is colorblind-friendly. Text color adapts
+          to background.
+      - id: VQ-05
+        name: Layout & Canvas
+        score: 3
+        max: 4
+        passed: true
+        comment: Good layout, minor imbalance from empty space in lower-right inherent
+          to triangular shape.
+      - id: VQ-06
+        name: Axis Labels & Title
+        score: 2
+        max: 2
+        passed: true
+        comment: 'Descriptive axis titles: Months Since Signup and Signup Cohort.'
+    design_excellence:
+      score: 12
+      max: 20
+      items:
+      - id: DE-01
+        name: Aesthetic Sophistication
+        score: 5
+        max: 8
+        passed: true
+        comment: Custom green colormap, rounded corners, cohort sizes, good typography
+          hierarchy. Above defaults but not publication-level.
+      - id: DE-02
+        name: Visual Refinement
+        score: 4
+        max: 6
+        passed: true
+        comment: Default axes hidden, cell gaps for breathing room, clean white background.
+      - id: DE-03
+        name: Data Storytelling
+        score: 3
+        max: 6
+        passed: false
+        comment: Triangular shape conveys retention decay. No strong focal point or
+          highlighted insight.
+    spec_compliance:
+      score: 15
+      max: 15
+      items:
+      - id: SC-01
+        name: Plot Type
+        score: 5
+        max: 5
+        passed: true
+        comment: Correct triangular cohort retention heatmap.
+      - id: SC-02
+        name: Required Features
+        score: 4
+        max: 4
+        passed: true
+        comment: 'All features present: triangular shape, retention percentages, cohort
+          sizes, colormap, colorbar.'
+      - id: SC-03
+        name: Data Mapping
+        score: 3
+        max: 3
+        passed: true
+        comment: Cohorts on Y-axis, periods on X-axis. Period 0 always 100%.
+      - id: SC-04
+        name: Title & Legend
+        score: 3
+        max: 3
+        passed: true
+        comment: Correct title format. Colorbar serves as legend.
+    data_quality:
+      score: 14
+      max: 15
+      items:
+      - id: DQ-01
+        name: Feature Coverage
+        score: 5
+        max: 6
+        passed: true
+        comment: Shows full retention decay, triangular shape, cohort variation, improvement
+          trend. Could have more dramatic variation.
+      - id: DQ-02
+        name: Realistic Context
+        score: 5
+        max: 5
+        passed: true
+        comment: SaaS monthly cohort retention. Neutral and realistic.
+      - id: DQ-03
+        name: Appropriate Scale
+        score: 4
+        max: 4
+        passed: true
+        comment: Realistic values for SaaS retention (100% to ~25% over 9 months).
+    code_quality:
+      score: 8
+      max: 10
+      items:
+      - id: CQ-01
+        name: KISS Structure
+        score: 1
+        max: 3
+        passed: false
+        comment: Custom class subclassing pygal Graph. Necessary for pygal but deviates
+          from flat structure.
+      - id: CQ-02
+        name: Reproducibility
+        score: 2
+        max: 2
+        passed: true
+        comment: np.random.seed(42) set.
+      - id: CQ-03
+        name: Clean Imports
+        score: 2
+        max: 2
+        passed: true
+        comment: All imports used.
+      - id: CQ-04
+        name: Code Elegance
+        score: 2
+        max: 2
+        passed: true
+        comment: Well-organized code, clean color interpolation, no fake UI.
+      - id: CQ-05
+        name: Output & API
+        score: 1
+        max: 1
+        passed: true
+        comment: Saves as plot.png and plot.svg.
+    library_mastery:
+      score: 8
+      max: 10
+      items:
+      - id: LM-01
+        name: Idiomatic Usage
+        score: 4
+        max: 5
+        passed: true
+        comment: Properly subclasses Graph with _plot()/_compute() overrides. Uses
+          SVG node system and Style class.
+      - id: LM-02
+        name: Distinctive Features
+        score: 4
+        max: 5
+        passed: true
+        comment: Uses pygal-specific Graph subclass, self.svg.node(), _tooltip_data(),
+          and Style system.
+  verdict: REJECTED
+impl_tags:
+  dependencies: []
+  techniques:
+  - colorbar
+  - annotations
+  - hover-tooltips
+  - html-export
+  patterns:
+  - data-generation
+  - matrix-construction
+  - iteration-over-groups
+  dataprep: []
+  styling:
+  - custom-colormap
+  - edge-highlighting