feat(letsplot): implement tree-phylogenetic

[github-actions]

Implementation: tree-phylogenetic - letsplot

Implements the letsplot version of tree-phylogenetic.

File: plots/tree-phylogenetic/implementations/letsplot.py

Parent Issue: #3070

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

The plot displays a phylogenetic tree (rectangular cladogram layout) showing primate evolutionary relationships. The tree has a blue color scheme (#306998) for branches and nodes, with leaf nodes color-coded by clade: blue for great apes (Human, Chimpanzee, Gorilla), yellow for lesser apes (Orangutan, Gibbon), and green for Old World monkeys (Macaque, Baboon, Mandrill). The x-axis shows "Evolutionary Distance (substitutions per site)" ranging from 0 to 0.85. Species labels appear to the right of each leaf node. The title reads "Primate Evolution · tree-phylogenetic · letsplot · pyplots.ai". Layout is horizontal with good use of canvas space.

Quality Score: 91/100

Criteria Checklist

Visual Quality (36/40 pts)

• VQ-01: Text Legibility (10/10) - Title is bold and large, axis labels are clear, species names are readable at 14pt
• VQ-02: No Overlap (8/8) - No overlapping text, species labels are well-spaced vertically
• VQ-03: Element Visibility (7/8) - Branch lines (size 1.5) and nodes (size 4-6) are clearly visible, though branch width could be slightly thicker
• VQ-04: Color Accessibility (5/5) - Blue, yellow, green clade colors are colorblind-safe and distinguishable
• VQ-05: Layout Balance (4/5) - Good horizontal layout filling canvas, but some empty space on right side beyond species labels
• VQ-06: Axis Labels (2/2) - X-axis has descriptive label with units "Evolutionary Distance (substitutions per site)"
• VQ-07: Grid & Legend (0/2) - No legend explaining clade colors; subtle grid only on x-axis which is appropriate

Spec Compliance (23/25 pts)

• SC-01: Plot Type (8/8) - Correct rectangular phylogenetic tree (cladogram) visualization
• SC-02: Data Mapping (5/5) - Branch lengths correctly proportional to evolutionary distance on x-axis
• SC-03: Required Features (4/5) - Has branch lengths, species labels, clade colors, but missing scale bar indicator
• SC-04: Data Range (3/3) - X-axis shows full evolutionary distance range (0 to 0.85)
• SC-05: Legend Accuracy (1/2) - No legend present to explain clade color coding
• SC-06: Title Format (2/2) - Correctly formatted: "Primate Evolution · tree-phylogenetic · letsplot · pyplots.ai"

Data Quality (18/20 pts)

• DQ-01: Feature Coverage (7/8) - Shows 8 primate species with varied branch lengths, demonstrates evolutionary divergence, but all leaf nodes end at similar x-positions
• DQ-02: Realistic Context (7/7) - Primate phylogeny based on mitochondrial DNA is a real, scientifically relevant scenario
• DQ-03: Appropriate Scale (4/5) - Branch lengths in substitutions per site are realistic, though some species (Mandrill, Baboon) should have longer terminal branches

Code Quality (9/10 pts)

• CQ-01: KISS Structure (2/3) - Contains helper functions (parse_newick, calc_x_positions, calc_y_positions) which adds complexity, but necessary for Newick parsing
• CQ-02: Reproducibility (3/3) - Deterministic Newick string input, no random elements
• CQ-03: Clean Imports (2/2) - Only uses re, pandas, and lets_plot - all necessary
• CQ-04: No Deprecated API (1/1) - Uses current lets-plot API
• CQ-05: Output Correct (1/1) - Saves as plot.png and plot.html

Library Features (5/5 pts)

• LF-01: Uses distinctive features (5/5) - Excellent use of lets-plot's ggplot2 grammar with geom_segment, geom_point, geom_text, scale_color_identity, theme customization, and ggsize/ggsave

Strengths

• Excellent implementation of rectangular phylogenetic tree using lets-plot's grammar of graphics
• Custom Newick parser handles complex nested structure correctly
• Color-coded clades (great apes, lesser apes, Old World monkeys) add visual interest
• Branch lengths accurately reflect evolutionary distances with proportional x-axis positioning
• Clean tree layout with horizontal and vertical segments properly connected
• Good use of theme_minimal with customized axis and grid settings

Weaknesses

• Missing legend to explain the three clade color groups (blue/yellow/green)
• Grid panel_grid_major_y is explicitly removed but no visual indicator of branch length scale (no scale bar)

Verdict: APPROVED