feat(ggplot2): implement smith-chart-basic

[github-actions]

Implementation: smith-chart-basic - r/ggplot2

Implements the r/ggplot2 version of smith-chart-basic.

File: plots/smith-chart-basic/implementations/r/ggplot2.R

Parent Issue: #3792

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

Light render (plot-light.png): Warm off-white background (#FAF8F1). Title "smith-chart-basic · r · ggplot2 · anyplot.ai" in dark ink, clearly readable. The Smith chart outer unit circle is drawn in soft dark gray (linewidth 0.7). Constant-resistance circles (r = 0, 0.2, 0.5, 1, 2, 5) and constant-reactance arcs (x = ±0.2, ±0.5, ±1, ±2, ±5) are rendered in a muted gray with alpha=0.65, creating a legible but unobtrusive grid. The impedance locus is a bold green (#009E73) curve sweeping from the lower-right (1 GHz) to just above the real axis (3 GHz), crossing through resonance near the center at 2 GHz. A green filled circle marks 1 GHz; an orange triangle (#D55E00) marks 3 GHz. A dashed blue (#0072B2) VSWR=2 reference circle is clearly visible. Frequency labels ("1 GHz", "2 GHz\n(res.)", "3 GHz") and resistance values along the real axis are present in soft gray. Axis labels Re(Γ) and Im(Γ) are in dark ink at 10pt, tick labels at 8pt. All primary text is readable against the light background. The small annotation texts (size≈6–7pt equivalent) are at the lower limit of comfortable mobile readability. Legibility verdict: PASS (with a note that annotation texts are small for mobile).

Dark render (plot-dark.png): Near-black background (#1A1A17). Title and axis labels render in light off-white/cream text, clearly readable — no dark-on-dark failures observed. Smith chart grid arcs and circles appear in a lighter warm gray, still visually distinct from the dark background. The impedance locus remains the same green (#009E73), the end marker the same orange (#D55E00), and the VSWR circle the same blue (#0072B2) — data colors are identical to the light render. The "VSWR = 2" and frequency labels are visible. Tick labels in INK_SOFT (#B8B7B0) read well against the dark surface. Brand green #009E73 remains clearly visible. No text is "dark on dark." Legibility verdict: PASS.

Both paragraphs confirmed. Both renders pass the theme-readability check.

Score: 89/100

Category	Score	Max
Visual Quality	28	30
Design Excellence	13	20
Spec Compliance	15	15
Data Quality	15	15
Code Quality	10	10
Library Mastery	8	10
Total	89	100

Visual Quality (28/30)

• VQ-01: Text Legibility (6/8) — Font sizes explicitly set (title=12, axis.title=10, axis.text=8). Main chrome is readable in both themes. However, annotation texts (size=2.1≈6pt for resistance values, size=2.4≈7pt for VSWR label, size=2.6≈7pt for frequency labels) are near the minimum for mobile readability after scaling from 2400px to 400px.
• VQ-02: No Overlap (6/6) — All text elements are well-positioned; frequency labels are offset from the locus points; grid elements do not obscure labels.
• VQ-03: Element Visibility (6/6) — Impedance locus at linewidth=1.4 is bold and prominent; start/end markers at size=3.5 are clearly visible; grid circles/arcs at linewidth=0.22 and alpha=0.65 are appropriately subtle.
• VQ-04: Color Accessibility (2/2) — Okabe-Ito palette is CVD-safe; three distinct colors used (green, orange, blue) are all distinguishable without relying on hue alone.
• VQ-05: Layout & Canvas (4/4) — Square 2400×2400 format is correct for a Smith chart. Chart fills the canvas well; asymmetric xlim (-1.15 to 1.35) provides space for right-side labels without wasting canvas.
• VQ-06: Axis Labels & Title (2/2) — Re(Γ) and Im(Γ) are descriptive with proper Greek notation. Title format is correct.
• VQ-07: Palette Compliance (2/2) — Locus uses #009E73 (Okabe-Ito Add workflow diagram for new prototype discovery #1); end marker uses #D55E00 (Add Claude Code GitHub Workflow #2); VSWR circle uses #0072B2 (Add Claude Code GitHub Workflow #3). Light background ≈ #FAF8F1; dark background ≈ #1A1A17. Theme-adaptive chrome is correct in both renders.

Design Excellence (13/20)

• DE-01: Aesthetic Sophistication (5/8) — Intentional color hierarchy (green locus, orange terminal, blue reference), appropriate visual weights for grid vs. data, clean professional appearance. Above "well-configured default" but not yet publication-ready — lacks that extra layer of polish (e.g., directional arrows on locus, focal emphasis at resonance point).
• DE-02: Visual Refinement (4/6) — Panel grid suppressed, all spines removed, theme-adaptive backgrounds, Smith chart grid drawn with appropriate alpha. Good refinement, but the overall composition could be pushed further.
• DE-03: Data Storytelling (4/6) — The resonance point is explicitly labeled "2 GHz (res.)", VSWR=2 reference circle provides engineering context, start/end markers differentiated by shape and color. The narrative — "antenna resonates at 2 GHz where impedance approaches the matched condition" — is legible from the plot.

Spec Compliance (15/15)

• SC-01: Plot Type (5/5) — Correct Smith chart with outer unit circle, constant-resistance circles, constant-reactance arcs, and impedance locus.
• SC-02: Required Features (4/4) — All required features present: resistance circles, reactance arcs, normalized impedance locus, frequency labels at key points, VSWR reference circle.
• SC-03: Data Mapping (3/3) — Re(Γ) on x-axis, Im(Γ) on y-axis; full 1–3 GHz sweep visible; reflection coefficient computed correctly via Γ=(z-1)/(z+1).
• SC-04: Title & Legend (3/3) — Title is exactly "smith-chart-basic · r · ggplot2 · anyplot.ai". No formal legend needed; inline labels serve the purpose.

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6) — Multiple resistance circles (r = 0,0.2,0.5,1,2,5) and reactance arcs (x = ±0.2,±0.5,±1,±2,±5); locus traverses both inductive (upper) and capacitive (lower) halves; resonance crossing on real axis clearly visible.
• DQ-02: Realistic Context (5/5) — Series RLC antenna model with resonance at 2 GHz; Z0=50Ω (standard RF reference); real-world RF/microwave engineering scenario, neutral topic.
• DQ-03: Appropriate Scale (4/4) — L=5nH and computed C giving f₀=2GHz are physically realistic; R=45Ω gives near-matched impedance; locus stays within |Γ|≤1; all values are physically plausible.

Code Quality (10/10)

• CQ-01: KISS Structure (3/3) — Linear flow: imports → theme tokens → grid data → locus data → labels → plot → save. No functions or classes.
• CQ-02: Reproducibility (2/2) — set.seed(42) present.
• CQ-03: Clean Imports (2/2) — Only library(ggplot2) and library(ragg); both actively used.
• CQ-04: Code Elegance (2/2) — Clean, appropriate complexity; lapply used efficiently for grid generation; no over-engineering; no fake interactivity.
• CQ-05: Output & API (1/1) — Saves as plot-{THEME}.png via ragg::agg_png device; no deprecated functions.

Library Mastery (8/10)

• LM-01: Idiomatic Usage (5/5) — Expert-level ggplot2: correct layer composition with geom_path/geom_point/geom_segment/annotate, proper use of aes(group=) for multi-path data, coord_fixed() for aspect ratio preservation, theme() chaining from theme_minimal().
• LM-02: Distinctive Features (3/5) — coord_fixed() is critical and ggplot2-specific; grammar-of-graphics layering for a complex technical chart is a genuine ggplot2 pattern. However, the core Smith chart construction (data generation for circles/arcs) is mostly base-R math outside ggplot2 itself.

Score Caps Applied

• None — no caps apply (VQ-02=6, VQ-03=6, SC-01=5, DQ-02=5, DE-01=5>2, CQ-04=2)

Strengths

• Perfect spec compliance — all required Smith chart elements present (resistance circles, reactance arcs, normalized locus, frequency labels, VSWR circle)
• Correct RF physics: RLC model with Γ=(z-1)/(z+1) reflection coefficient transform implemented accurately
• Excellent theme adaptation — both renders correctly use theme-adaptive chrome with identical data colors
• coord_fixed() preserves the critical circular geometry of the Smith chart
• Okabe-Ito palette applied in correct canonical order (#009E73 locus, #D55E00 terminal, #0072B2 reference)
• Realistic, neutral data scenario (antenna impedance matching in RF engineering)
• Clean, idiomatic ggplot2 code with efficient lapply-based grid construction

Weaknesses

• Annotation text sizes are small: size=2.1 (≈6pt) for resistance axis labels and size=2.4–2.6 (≈7pt) for VSWR and frequency labels — at the low end for mobile readability after 6× downscale from 2400px to 400px; increase to size=2.8–3.2 for all secondary annotations
• Design Excellence at 13/20 keeps the score just below 90 — adding a directional indicator on the locus (e.g., arrowhead or tick marks at 0.5 GHz intervals) would improve storytelling (DE-03) and visual sophistication (DE-01)

Issues Found

1. VQ-01 SMALL ANNOTATIONS: Resistance axis labels (size=2.1≈6pt) and VSWR/frequency labels (size=2.4–2.6≈7pt) may be too small after scaling to mobile viewport
   • Fix: Increase resistance value labels to size=2.5–2.8, frequency labels to size=3.0–3.2
2. DE-01/DE-03 MODERATE: Missing directional cue on impedance locus — reader cannot immediately see which direction the frequency sweeps without the "1 GHz" / "3 GHz" labels
   • Fix: Add arrow = arrow(length = unit(0.2, "cm"), type = "closed") to the locus geom_path or add small tick marks at intermediate frequency points to show sweep direction

AI Feedback for Next Attempt

Slightly increase annotation text sizes (size=2.5+ for resistance labels, size=3.0+ for frequency labels) to ensure mobile readability at 400px. Add a directional indicator to the impedance locus (arrowhead or intermediate frequency ticks at 1.5 and 2.5 GHz) to make the frequency sweep direction self-evident without relying solely on endpoint labels — this will improve both DE-01 and DE-03. The underlying physics, palette, theme adaptation, and code quality are all excellent; only these two refinements are needed to reach 90+.

Verdict: REJECTED

[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`): The plot displays on a warm off-white (#FAF8F1) background. The Smith chart features a prominent outer unit circle and subtle gray constant-resistance circles and reactance arcs (alpha=0.65, linewidth=0.22) arranged in the standard circular topology. The primary impedance locus is drawn in #009E73 (brand green) as a thick connected curve sweeping from 1 GHz (lower right, circle marker) through the resonance near chart center at 2 GHz, to 3 GHz (upper center, orange triangle). A directional arrow at the 3 GHz end indicates sweep direction. A dashed blue VSWR=2 reference circle (#0072B2) sits near the center-left. Frequency labels ("1 GHz", "2 GHz\n(res.)", "3 GHz") and resistance-axis values (0, 0.2, 0.5, 1, 2, 5) are all clearly readable in dark ink. Title "smith-chart-basic · r · ggplot2 · anyplot.ai", axis labels "Re(Γ)"/"Im(Γ)", and tick labels are all clearly visible against the light background. Legibility verdict: PASS.

Dark render (`plot-dark.png`): The same chart renders on a warm near-black (#1A1A17) background. The outer unit circle and Smith chart grid appear in light gray (#B8B7B0, INK_SOFT for dark theme), providing good contrast against the dark surface. The impedance locus retains its #009E73 green color — identical to the light render — confirming correct data/chrome separation. The orange triangle end marker (#D55E00) and blue VSWR circle (#0072B2) are also unchanged. Title, axis labels, and tick labels appear in off-white (#F0EFE8) and are clearly legible. Frequency labels use INK (dark-theme: #F0EFE8) and are readable. No dark-on-dark text failures observed. Legibility verdict: PASS.

Score: 89/100

Category	Score	Max
Visual Quality	29	30
Design Excellence	13	20
Spec Compliance	15	15
Data Quality	15	15
Code Quality	10	10
Library Mastery	7	10
Total	89	100

Visual Quality (29/30)

• VQ-01: Text Legibility (7/8) — All font sizes explicitly set (title=12, axis.title=10, axis.text=8). Readable in both themes. Annotation labels (size=3.0–3.2 ≈ 47–50 px) are slightly small when scaled to mobile (~8 px).
• VQ-02: No Overlap (6/6) — Frequency labels and resistance-axis labels are well-spaced. No collisions between text and data elements.
• VQ-03: Element Visibility (6/6) — Impedance locus (linewidth=1.4) dominates appropriately; grid lines (linewidth=0.22, alpha=0.65) are subtle reference lines. Start/end markers (size=3.5) are clearly visible.
• VQ-04: Color Accessibility (2/2) — Okabe-Ito palette throughout; green vs orange vs blue all CVD-safe and distinguishable without relying on hue alone.
• VQ-05: Layout & Canvas (4/4) — Square 6×6 in @ 400 dpi (2400×2400 px) is the correct format choice for the circular Smith chart. Chart fills canvas well with balanced margins.
• VQ-06: Axis Labels & Title (2/2) — "Re(Γ)" and "Im(Γ)" use proper mathematical notation. Title uses mandated format.
• VQ-07: Palette Compliance (2/2) — Primary locus uses #009E73 (Okabe-Ito Add workflow diagram for new prototype discovery #1). Secondary elements follow Okabe-Ito order (#D55E00 end marker, #0072B2 VSWR circle). Backgrounds #FAF8F1/#1A1A17, never pure white/black. Both themes chrome-correct.

Design Excellence (13/20)

• DE-01: Aesthetic Sophistication (5/8) — Domain-aware design: directional arrow on sweep, distinct start (circle) vs end (triangle) markers, grid weight hierarchy (outer=0.7, inner=0.22), subtle alpha on grid lines. Above a generic default but not yet publication-ready polish.
• DE-02: Visual Refinement (4/6) — Panel grid removed and replaced with custom Smith chart geometry. Outer circle heavier than internal arcs creating proper hierarchy. Real axis line explicit. Could further refine resistance label positioning and outer-circle annotation style.
• DE-03: Data Storytelling (4/6) — Directional arrow communicates frequency sweep direction. "2 GHz (res.)" annotation highlights the resonance phenomenon. VSWR=2 reference circle provides engineering context. Matched-load center marker adds domain knowledge. Clear RF engineering narrative.

Spec Compliance (15/15)

• SC-01: Plot Type (5/5) — Complete Smith chart: outer unit circle, constant-r circles (r=0, 0.2, 0.5, 1, 2, 5), constant-x arcs (x=±0.2, ±0.5, ±1, ±2, ±5), impedance locus, VSWR circle, center marker.
• SC-02: Required Features (4/4) — All spec requirements met: normalized impedance (Z/Z0), connected locus curve, frequency labels at key points, VSWR circle, boundary at |Γ|=1, center marker at matched condition.
• SC-03: Data Mapping (3/3) — Re(Γ) on x-axis, Im(Γ) on y-axis, all data visible within unit circle.
• SC-04: Title & Legend (3/3) — Title "smith-chart-basic · r · ggplot2 · anyplot.ai" matches required format. Frequency points labeled inline with text annotations.

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6) — Shows all aspects: full resistance/reactance grid, impedance sweep through capacitive and inductive regions, resonance crossing, VSWR reference, sweep direction.
• DQ-02: Realistic Context (5/5) — Real RLC antenna model (L=5 nH, C computed for exact 2 GHz resonance, R=45 Ω ≈ 50 Ω matched). 50 Ω reference impedance is the RF engineering standard. 1–3 GHz range is plausible UHF/microwave.
• DQ-03: Appropriate Scale (4/4) — Physically correct: at 2 GHz resonance Γ ≈ -0.053 (near-matched condition), VSWR=2 circle at |Γ|=1/3, locus shape correctly traces through capacitive (lower) and inductive (upper) half-planes.

Code Quality (10/10)

• CQ-01: KISS Structure (3/3) — Linear flow: imports → theme tokens → grid generation → data → plot → save. No functions or classes.
• CQ-02: Reproducibility (2/2) — set.seed(42) present. Data is deterministic (computed from RLC physics).
• CQ-03: Clean Imports (2/2) — Only ggplot2 and ragg imported, both used.
• CQ-04: Code Elegance (2/2) — do.call(rbind, lapply(...)) is idiomatic R. Arc clipping to unit disc via vector boolean indexing is clean. No over-engineering.
• CQ-05: Output & API (1/1) — sprintf("plot-%s.png", THEME) produces correct filenames. ragg::agg_png device used.

Library Mastery (7/10)

• LM-01: Idiomatic Usage (4/5) — coord_fixed() for preserving circular geometry, annotate() with arrow() for directional arrow, geom_path with group for multiple circles, theme_minimal with layered overrides. All idiomatic.
• LM-02: Distinctive Features (3/5) — coord_fixed() and annotate with arrow() are ggplot2-specific. The layered grammar naturally builds up the chart. Could push further with ggplot2-specific annotation or scale features.

Score Caps Applied

• None

Strengths

• Physically correct Smith chart geometry: constant-r circles and constant-x arcs computed from proper formulas, arc clipping to unit disc handled cleanly
• Domain-aware data: real RLC antenna model with exact 2 GHz resonance, physically correct Γ trajectory
• Full spec coverage: all required features present (grid, normalized locus, frequency labels, VSWR circle, center marker)
• Both themes correctly implemented with INK/INK_SOFT/PAGE_BG tokens; data colors identical across themes, only chrome flips
• Excellent code quality: idiomatic R/ggplot2, KISS structure, deterministic data

Weaknesses

• Annotation text (frequency labels, resistance labels, VSWR label) at size=3.0–3.2 ≈ 47–50 px is slightly small for mobile (~8 px when scaled to 400 px width); consider 3.5–4.0
• DE-01/DE-02: Visual polish could improve — resistance labels below real axis are positioned but lack typographic finesse; consider adding a subtle label for the outer circle ("|Γ|=1") or more elegant resistance annotations
• LM-02: coord_polar is not appropriate here, but could leverage ggplot2's annotate("rect") or geom_ribbon for highlighting VSWR zones

Issues Found

1. VQ-01 MINOR: Annotation text slightly small for mobile — size=3.0–3.2 in geom units (~47–50 px) scales to ~8 px at 400 px mobile width
   • Fix: Increase annotation text to size=3.5–4.0
2. DE-01/DE-02 MEDIUM: Polish gap — resistance labels are functional but lack visual integration (e.g., they appear below the real axis at y=-0.06 without a clear typographic treatment)
   • Fix: Consider slightly larger resistance labels, or add tick-mark style lines; refine VSWR label placement

AI Feedback for Next Attempt

The implementation is strong (89/100) — spec coverage perfect, data quality perfect, code quality perfect. To push higher: increase annotation text sizes slightly (size=3.5 for frequency labels, size=3.2 for resistance labels) for better mobile readability. For Design Excellence, add a subtle "|Γ|=1" label on the outer boundary, and consider a very faint shaded region for VSWR > 2 zone to strengthen visual hierarchy and storytelling.

Verdict: APPROVED