feat(bokeh): implement smith-chart-basic

[github-actions]

Implementation: smith-chart-basic - bokeh

Implements the bokeh version of smith-chart-basic.

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

Parent Issue: #3792

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

The plot shows a Smith chart with the classic circular impedance coordinate system. A blue outer boundary represents the unit circle (|Γ| = 1). Gray constant resistance circles (r = 0.2, 0.5, 1, 2) are visible emanating from the right side, and gray constant reactance arcs curve symmetrically above and below the horizontal axis. A yellow impedance locus curve with circular markers traces a frequency sweep from 1.0 GHz to 6.0 GHz, forming a characteristic loop pattern in the right half of the chart. Frequency labels (1.0 GHz, 2.2 GHz, 3.6 GHz, 4.8 GHz, 6.0 GHz) are placed at key points along the locus in blue text. A dark blue marker at the center marks the matched condition (Z=Z₀). Small gray labels indicate r-values (r=0.2, r=0.5, r=1, r=2) along the horizontal axis and x-values (x=0.5, x=1, x=2) on the boundary arcs. The title "smith-chart-basic · bokeh · pyplots.ai" appears at top-left. Axes are labeled "Real(Γ)" and "Imag(Γ)". The background is light gray (#fafafa).

Quality Score: 91/100

Criteria Checklist

Visual Quality (36/40 pts)

• VQ-01: Text Legibility (9/10) - Title, axis labels, and frequency annotations are clearly readable at high resolution. Some r/x labels on the grid are small but still legible.
• VQ-02: No Overlap (8/8) - No overlapping text elements; frequency labels are well-positioned with offsets.
• VQ-03: Element Visibility (7/8) - Impedance locus markers (size=14) and line (width=5) are clearly visible. The matched condition marker is prominent.
• VQ-04: Color Accessibility (5/5) - Yellow/gold (#FFD43B) locus against blue (#306998) boundary provides excellent contrast. Gray grid lines are subtle. Colorblind-safe.
• VQ-05: Layout Balance (5/5) - Square aspect ratio is appropriate for Smith chart. Good utilization of canvas with x_range/y_range (-1.35, 1.35) providing balanced margins.
• VQ-06: Axis Labels (1/2) - Labels "Real(Γ)" and "Imag(Γ)" are descriptive but lack explicit units (dimensionless coefficient).
• VQ-07: Grid & Legend (1/2) - Grid alpha=0.4 is appropriate; no explicit legend but frequency labels serve the purpose.

Spec Compliance (24/25 pts)

• SC-01: Plot Type (8/8) - Correct Smith chart implementation with constant resistance circles and reactance arcs.
• SC-02: Data Mapping (5/5) - Impedance correctly normalized (Z/Z0) and converted to reflection coefficient Γ.
• SC-03: Required Features (4/5) - Has resistance circles, reactance arcs, impedance locus, frequency labels, matched condition marker. VSWR circles noted as optional in spec and not included.
• SC-04: Data Range (3/3) - Chart shows full unit circle with appropriate padding.
• SC-05: Legend Accuracy (2/2) - Labels correctly identify frequency points and r/x values.
• SC-06: Title Format (2/2) - Correct format: "smith-chart-basic · bokeh · pyplots.ai"

Data Quality (18/20 pts)

• DQ-01: Feature Coverage (7/8) - Shows impedance variation with frequency, resonance behavior, both positive and negative reactance regions. Could show more variation in the pattern.
• DQ-02: Realistic Context (7/7) - Excellent RF engineering scenario: antenna S11 sweep 1-6 GHz with series RLC resonance model at 3.5 GHz, Q=5.
• DQ-03: Appropriate Scale (4/5) - R=45-55Ω, X varies realistically. Z0=50Ω standard reference impedance.

Code Quality (10/10 pts)

• CQ-01: KISS Structure (3/3) - Linear script: imports → constants → figure → grid drawing → data generation → plotting → save.
• CQ-02: Reproducibility (3/3) - np.random.seed(42) set for reproducibility.
• CQ-03: Clean Imports (2/2) - All imports used: numpy, bokeh.io, bokeh.models, bokeh.plotting.
• CQ-04: No Deprecated API (1/1) - Uses current Bokeh API.
• CQ-05: Output Correct (1/1) - Saves as plot.png and plot.html.

Library Features (3/5 pts)

• LF-01: Distinctive Features (3/5) - Uses ColumnDataSource, Label annotations, export_png, and saves interactive HTML. Could utilize HoverTool for interactive impedance/frequency display.

Strengths

• Mathematically correct Smith chart implementation with proper constant-r circles and constant-x arcs
• Excellent realistic RF engineering data scenario with antenna resonance model
• Clean visual hierarchy with yellow locus standing out against blue/gray grid
• Good use of Bokeh features: ColumnDataSource, Label annotations, both PNG and HTML export
• Proper normalization and gamma conversion mathematics
• Well-positioned frequency labels with offset to avoid overlap with data points

Weaknesses

• Could add HoverTool for interactive impedance/frequency inspection in the HTML version
• Grid r/x labels are slightly small compared to other text elements
• Axis labels could include "(dimensionless)" clarification

Verdict: APPROVED