feat(plotly): implement smith-chart-basic

[github-actions]

Implementation: smith-chart-basic - plotly

Implements the plotly version of smith-chart-basic.

File: plots/smith-chart-basic/implementations/plotly.py

Parent Issue: #3792

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

The plot displays a Smith chart for RF/impedance visualization. The chart features a blue circular boundary representing |Γ| = 1 (total reflection). Inside, gray constant resistance circles and constant reactance arcs form the characteristic Smith chart grid. The impedance locus is plotted as a connected curve with blue lines (width ~4) and yellow circular markers with blue outlines. Four frequency labels (1.0 GHz, 2.6 GHz, 4.3 GHz, 6.0 GHz) are annotated with arrows pointing to their respective positions on the curve, displayed in boxed labels with blue borders. A yellow X marker at the center indicates the matched condition (Z = Z₀). The legend in the upper-left shows 'Impedance Locus' and 'Matched (Z = Z₀)'. Axis labels read 'Real(Γ)' and 'Imag(Γ)' with tick fonts appropriately sized. The title follows the correct format: 'smith-chart-basic · plotly · pyplots.ai'. Resistance labels (0, 0.2, 0.5, 1, 2, 5) appear along the horizontal axis, and reactance labels (+j0.5, -j0.5, +j1, -j1) are placed near the chart boundary.

Quality Score: 91/100

Criteria Checklist

Visual Quality (36/40 pts)

• VQ-01: Text Legibility (10/10) - Title at 28pt, axis labels at 22pt, tick fonts at 18pt, annotation fonts at 16pt - all clearly readable
• VQ-02: No Overlap (8/8) - Frequency labels positioned with offsets to avoid overlap, no text collisions
• VQ-03: Element Visibility (7/8) - Markers at size=10 with yellow fill and blue outline are visible, line width=4 is good, but could be slightly larger for 50 data points
• VQ-04: Color Accessibility (5/5) - Blue (#306998) and yellow (#FFD43B) provide excellent contrast, colorblind-safe
• VQ-05: Layout Balance (4/5) - Chart is well-centered but axis range extends to ±2.0 while chart is ±1.15, creating some unused space
• VQ-06: Axis Labels (2/2) - 'Real(Γ)' and 'Imag(Γ)' are descriptive with Greek symbols
• VQ-07: Grid & Legend (0/2) - Grid uses alpha=0.4 which is acceptable, but legend is positioned in upper-left corner far from the plot area, somewhat isolated

Spec Compliance (25/25 pts)

• SC-01: Plot Type (8/8) - Correct Smith chart with constant resistance circles and constant reactance arcs
• SC-02: Data Mapping (5/5) - Impedance correctly normalized and converted to reflection coefficient (gamma)
• SC-03: Required Features (5/5) - Has grid, impedance locus curve, frequency labels, matched condition marker as specified
• SC-04: Data Range (3/3) - All data visible within the unit circle boundary
• SC-05: Legend Accuracy (2/2) - Legend correctly identifies 'Impedance Locus' and 'Matched (Z = Z₀)'
• SC-06: Title Format (2/2) - Correct format: 'smith-chart-basic · plotly · pyplots.ai'

Data Quality (18/20 pts)

• DQ-01: Feature Coverage (7/8) - Shows frequency sweep trajectory through different impedance regions (inductive to capacitive), but doesn't explicitly show VSWR circles (optional per spec)
• DQ-02: Realistic Context (7/7) - Antenna impedance sweep from 1-6 GHz is a realistic RF engineering scenario
• DQ-03: Appropriate Scale (4/5) - Z0=50Ω is standard, impedance values are realistic but the random noise added to z_real introduces some jaggedness

Code Quality (9/10 pts)

• CQ-01: KISS Structure (3/3) - Linear flow: imports → data → plot → save, no functions/classes
• CQ-02: Reproducibility (3/3) - np.random.seed(42) is set
• CQ-03: Clean Imports (2/2) - Only numpy and plotly.graph_objects imported, both used
• CQ-04: No Deprecated API (1/1) - Uses current Plotly API
• CQ-05: Output Correct (0/1) - Saves as plot.png and plot.html but should be just plot.png for primary output review

Library Features (3/5 pts)

• LF-01: Distinctive Features (3/5) - Uses Plotly's interactive hover with custom text, annotations with arrows, but doesn't leverage more advanced features like custom colorscales or animation

Strengths

• Excellent implementation of Smith chart grid with proper constant resistance circles and constant reactance arcs clipped to unit circle
• Proper RF engineering math: impedance normalization and reflection coefficient calculation are correct
• Well-designed frequency annotations with arrow pointers and varied positions to avoid overlap
• Interactive hover text shows frequency and complex impedance values
• Clean visual hierarchy with blue primary color and yellow accent markers

Weaknesses

• Axis range extends to ±2.0 while the Smith chart boundary is at ±1.15, leaving unused whitespace outside the chart
• Legend placement in upper-left corner is somewhat isolated from the chart area

Verdict: APPROVED