feat(letsplot): implement candlestick-volume

[github-actions]

Implementation: candlestick-volume - python/letsplot

Implements the python/letsplot version of candlestick-volume.

File: plots/candlestick-volume/implementations/python/letsplot.py

Parent Issue: #3068

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

Light render (plot-light.png): The plot displays a professional candlestick chart with volume bars using a warm off-white background (#FAF8F1). The main pane shows OHLC candlesticks with green wicks/bodies for up days (#009E73) and orange for down days (#D55E00), clearly representing price movement from ~$150 to $115-$170 over 60 trading days. The volume pane below shows stacked bars in the same color scheme, with volume ranging from 3.9M to 10.1M shares. The x-axis displays date labels every 10 trading days. All text is clearly readable: dark title, axis labels, and tick labels (medium gray) contrast well against the light background. Grid lines are subtle and unobtrusive. However, the title is truncated at the right edge—"anyplot.ai" is cut off, affecting full readability. Legibility verdict: PASS (with caveat: title truncated).

Dark render (plot-dark.png): The dark render maintains identical data colors (#009E73 for up, #D55E00 for down) confirming proper theme adaptation. The background is warm near-black (#1A1A17), and all text is rendered in light colors: white/light-gray title and labels provide excellent contrast. Candlesticks and volume bars are equally visible against the dark surface. Grid lines are subtle and visible. No dark-on-dark failures detected. The layout and proportions are identical to the light render. However, the title is similarly truncated at the right edge. Legibility verdict: PASS (with caveat: title truncated).

Both renders theme-correct: Okabe-Ito data colors identical across themes, chrome properly inverted (light text on dark, dark text on light). Main legibility issue is title truncation, not theme adaptation.

Score: 83/100

Category	Score	Max
Visual Quality	25	30
Design Excellence	12	20
Spec Compliance	13	15
Data Quality	15	15
Code Quality	10	10
Library Mastery	8	10
Total	83	100

Visual Quality (25/30)

• VQ-01: Text Legibility (5/8) - Font sizes explicitly set; visible text readable. Title truncated at right edge.
• VQ-02: No Overlap (6/6) - No overlapping elements; all text distinct.
• VQ-03: Element Visibility (6/6) - Candlesticks and volume bars perfectly visible for 60-point dataset.
• VQ-04: Color Accessibility (2/2) - Okabe-Ito colors provide strong contrast; CVD-safe.
• VQ-05: Layout & Canvas (2/4) - Correct dimensions and pane ratio; title cut off at right edge (content not fully visible).
• VQ-06: Axis Labels & Title (2/2) - All axes descriptive with units (Price $, Volume shares, Date context).
• VQ-07: Palette Compliance (2/2) - Perfect: #FAF8F1 light / #1A1A17 dark backgrounds; #009E73 / #D55E00 Okabe-Ito colors identical across themes; theme-adaptive text colors.

Design Excellence (12/20)

• DE-01: Aesthetic Sophistication (4/8) - Well-configured with theme tokens and correct Okabe-Ito palette; competent but follows defaults without exceptional touches.
• DE-02: Visual Refinement (4/6) - Subtle grid (size=0.25), generous margins, clean legend. Spines remain visible; could remove top/right for cleaner appearance.
• DE-03: Data Storytelling (4/6) - Clear visualization of trading dynamics with color-coded direction and correlated volume. Good visual hierarchy.

Spec Compliance (13/15)

• SC-01: Plot Type (5/5) - Correct candlestick chart with dual-pane volume layout.
• SC-02: Required Features (3/4) - Candlesticks (wicks + bodies), volume bars, shared x-axis, up/down coloring present. Missing: interactive crosshair/cursor (static library limitation).
• SC-03: Data Mapping (3/3) - X-axis time, price pane Y-axis OHLC, volume pane Y-axis volume. All data visible.
• SC-04: Title & Legend (2/3) - Title deviates from spec format (includes "Stock Trading" prefix; should be "{spec-id} · {library} · anyplot.ai"). Legend labels correct.

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6) - Shows all aspects: bullish/bearish candles, wicks, dramatic reversals, volume spikes.
• DQ-02: Realistic Context (5/5) - Real stock trading scenario; 60 trading days; realistic prices ($115-$170) and volumes (3.9M-10.1M).
• DQ-03: Appropriate Scale (4/4) - Volatility ~15%, volume scaling realistic, returns normally distributed.

Code Quality (10/10)

• CQ-01: KISS Structure (3/3) - Linear flow: imports → theme → data → plot → save. No functions/classes.
• CQ-02: Reproducibility (2/2) - np.random.seed(42) set; fully deterministic.
• CQ-03: Clean Imports (2/2) - Only used imports: os, numpy, pandas, lets_plot.
• CQ-04: Code Elegance (2/2) - Clean, Pythonic, appropriate complexity.
• CQ-05: Output & API (1/1) - Saves plot-{THEME}.png and plot-{THEME}.html with correct scale=3.

Library Mastery (8/10)

• LM-01: Idiomatic Usage (4/5) - Correct ggplot() + geom_* + theme() patterns. Standard usage; could leverage more advanced patterns.
• LM-02: Distinctive Features (4/5) - Uses gggrid() for layout, ggsize() for dimensions, HTML output. Some library-specific features demonstrated.

Score Caps Applied

• None - no caps apply

Strengths

• Excellent data quality: realistic OHLC generation with correlated volume spikes showing trading patterns
• Perfect theme implementation: both renders properly adapt colors (data unchanged, chrome theme-correct) with no dark-on-dark failures
• Strong spec compliance: candlestick + volume dual-pane layout with correct up/down color coding (Okabe-Ito Add workflow diagram for new prototype discovery #1 green, Add Claude Code GitHub Workflow #2 orange)
• High code quality: clean KISS structure, deterministic seed, proper theme tokens, idiomatic letsplot usage with gggrid() for layout
• Professional styling: subtle grid, appropriate margins, clean legend positioning, readable text at full resolution

Weaknesses

• Title truncated at right edge (VQ-01/VQ-05): Title text is cut off preventing full readability of "anyplot.ai" suffix. Increase canvas width or reduce title length.
• Title format deviation (SC-04): Uses "Stock Trading · candlestick-volume · letsplot" instead of spec format "{spec-id} · {library} · anyplot.ai". Remove "Stock Trading" prefix.
• Missing interactive features (SC-02): Spec mentions crosshair/cursor for precise reading across panes. Static library limitation—consider documenting in code comment.
• Design excellence (DE-01): Competent execution but follows defaults without exceptional aesthetic touches. Consider refined color harmony or visual hierarchy enhancements.
• Spines remain visible (DE-02): Standard practice would remove top/right spines for cleaner appearance. Consider spine removal for next iteration.

Issues Found

1. VQ-01/VQ-05 CRITICAL: Title truncated at right edge
   • Fix: Increase base canvas width (e.g., 1700×900) or shorten title to fit within current dimensions
2. SC-04 MINOR: Title format includes "Stock Trading" prefix
   • Fix: Use spec format only: "candlestick-volume · letsplot · anyplot.ai"

AI Feedback for Next Attempt

High confidence approval on this review. The implementation is well-executed with excellent data quality, perfect theme adaptation, and correct color palette. Score 83/100 meets Review 2 threshold (≥80). Main fixes needed: (1) Title truncation—adjust canvas or shorten title to fit; (2) Title format—remove "Stock Trading" prefix to match spec; (3) Optional refinements—remove top/right spines (DE-02), consider enhanced visual hierarchy (DE-03). Static library cannot implement interactive crosshair, but this is documented and understandable.

Verdict: APPROVED ✅

[github-actions]

🔧 Repair Attempt 1/4

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

Light render (plot-light.png): A professional dual-pane candlestick-volume chart rendered on a warm off-white background (#FAF8F1). The main candlestick pane occupies the upper ~70% of the chart showing 60 trading days of price data with teal green (#009E73) candlesticks for "Up" days and orange (#D55E00) candlesticks for "Down" days. Wicks (vertical lines showing high-low range) and bodies (thicker segments showing open-close) are clearly distinct. The Y-axis labeled "Price ($)" displays values from 115 to 170 with dark tick labels that are fully readable against the light background. The X-axis shows dates (Jan 02, Jan 16, Jan 30, Feb 13, Feb 27, Mar 12) with no overlap. A horizontal legend at the top center reads "Direction — Up — Down". The lower volume pane shows volume bars in the same green/orange scheme with a Y-axis labeled "Volume (shares)" showing values 3.9M, 7.0M, 10.1M. Subtle grid lines are visible but not dominant. All text elements (title, axis labels, tick labels, legend) are explicitly sized (24pt, 20pt, 16pt respectively) and perfectly readable at full resolution. Both panes share a common x-axis for time alignment. Legibility verdict: PASS - all text is dark and clear against the warm light background.

Dark render (plot-dark.png): The same chart rendered on a warm near-black background (#1A1A17) with all chrome colors inverted appropriately. The candlestick colors are identical to the light render (same green #009E73 and orange #D55E00), confirming proper data-color invariance across themes. Title text is now white and clearly readable. Axis labels and tick labels are rendered in light colors (INK_SOFT token #B8B7B0) that contrast well against the dark background. Grid lines remain subtle in the dark theme. The volume pane shows the same data with identical color coding. No "dark-on-dark" failures - all text is light and readable, no near-black text on near-black background. The dual-pane layout maintains proper alignment between price and volume axes. Legibility verdict: PASS - all text is light and clear against the warm dark background. Data colors are identical to light render, only chrome has theme-adapted appropriately.

Score: 90/100

Category	Score	Max
Visual Quality	30	30
Design Excellence	10	20
Spec Compliance	15	15
Data Quality	15	15
Code Quality	10	10
Library Mastery	10	10
Total	90	100

Visual Quality (30/30)

• VQ-01: Text Legibility (8/8) - All font sizes explicitly set (title 24pt, labels 20pt, ticks 16pt); perfectly readable in both themes
• VQ-02: No Overlap (6/6) - Date labels, tick labels, legend all clearly separated with no collision
• VQ-03: Element Visibility (6/6) - Candlestick wicks (1.5px) and bodies (6.0px) optimally sized for 60-day data density; volume bars (0.8 width) clearly distinct
• VQ-04: Color Accessibility (2/2) - Okabe-Ito palette (#009E73, #D55E00) is colorblind-safe; good luminance contrast between series
• VQ-05: Layout & Canvas (4/4) - Landscape 4800×2700px with excellent utilization; candlestick pane 70%, volume pane 30%; balanced margins (40,20,2,10)
• VQ-06: Axis Labels & Title (2/2) - Descriptive labels with units: "Price ($)", "Volume (shares)", "Date (2024)"
• VQ-07: Palette Compliance (2/2) - First series is brand green #009E73; second is Okabe-Ito orange #D55E00; backgrounds correctly set (#FAF8F1 light / #1A1A17 dark); text colors theme-correct in both renders (INK and INK_SOFT tokens applied consistently)

Design Excellence (10/20)

• DE-01: Aesthetic Sophistication (4/8) - Okabe-Ito palette applied intentionally; theme-adaptive design with explicit token usage; looks like a well-configured library default, not exceptional or publication-ready
• DE-02: Visual Refinement (4/6) - Subtle grid (0.25px), thoughtful legend positioning (top center, horizontal), generous margins, dual-pane structure shows refinement; some customization visible
• DE-03: Data Storytelling (2/6) - Data displays clearly with visual hierarchy (price dominant, volume supporting), but no strong focal point or narrative emphasis through color/size variation

Spec Compliance (15/15)

• SC-01: Plot Type (5/5) - Correct candlestick chart with OHLC structure (wicks and bodies) plus volume bars in dual-pane layout
• SC-02: Required Features (4/4) - Candlesticks ✓, volume bars ✓, dual-pane layout ✓, shared x-axis ✓, up/down color consistency ✓ (interactive crosshair not expected in static PNG)
• SC-03: Data Mapping (3/3) - X-axis: date index with proper labels; Y-axes: price in dollars and volume in shares; all data visible and correctly mapped
• SC-04: Title & Legend (3/3) - Title format correct: "candlestick-volume · letsplot · anyplot.ai"; legend labels match: "Direction — Up — Down"

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6) - Shows bullish candles ✓, bearish candles ✓, high volatility periods ✓, low volatility periods ✓, volume-volatility correlation ✓
• DQ-02: Realistic Context (5/5) - Stock trading data (neutral, real-world scenario), 60 trading days (3-month realistic timeframe), price range $115-$170 (plausible), volume range 3.9M-10.1M (realistic)
• DQ-03: Appropriate Scale (4/4) - Price evolution realistic (uptrend → reversal → recovery); volume distribution correlates with volatility; all values factually plausible

Code Quality (10/10)

• CQ-01: KISS Structure (3/3) - Linear flow: Imports → Data generation → Theme setup → Plot creation → Save; no functions/classes
• CQ-02: Reproducibility (2/2) - np.random.seed(42) set; all data generation deterministic
• CQ-03: Clean Imports (2/2) - Only necessary imports (os, numpy, pandas, lets_plot); no extraneous dependencies
• CQ-04: Code Elegance (2/2) - Clean, Pythonic, appropriate complexity; no fake interactive elements; helper logic for date/volume formatting is reasonable
• CQ-05: Output & API (1/1) - Saves as plot-{THEME}.png and plot-{THEME}.html; uses current letsplot API

Library Mastery (10/10)

• LM-01: Idiomatic Usage (5/5) - Expertly uses ggplot() + geom_*() pattern; proper use of scale_color_manual(), theme(), gggrid(), ggsave() with scale parameter
• LM-02: Distinctive Features (5/5) - Uses gggrid() for dual-pane layout (distinctive to letsplot), theme-adaptive styling with element_*() functions, geom_segment() for candlestick construction

Score Caps Applied

• None - No defects trigger score caps

Strengths

• Perfect visual quality across both light and dark themes with no readability issues
• Excellent use of letsplot's gggrid() for dual-pane layout with proper spacing (70/30 split)
• Comprehensive theme-adaptive styling with consistent INK and INK_SOFT token usage throughout
• Data is realistic and demonstrates clear features (uptrend, reversal, recovery, volume correlation)
• Proper font sizing (24/20/16pt) with explicit configuration, not relying on defaults
• Candlestick visualization is technically correct with distinct wicks and bodies
• Clean code with good KISS structure and proper reproducibility (seed)

Weaknesses

• Design sophistication is serviceable but not exceptional - follows standard financial chart patterns rather than adding unique visual storytelling
• Data storytelling is minimal - plot displays data clearly but lacks strong visual hierarchy or emphasis to guide viewer insights
• Limited use of visual emphasis techniques (color contrast, size variation, focal points) to create narrative

Issues Found

None - implementation is high quality and ready to merge.

AI Feedback for Next Attempt

N/A - APPROVED at 90/100. For future enhancements, consider adding subtle visual emphasis to correlate price movements with volume spikes, or using color/opacity variations to highlight significant trading days or reversals.

Verdict: APPROVED