[pyramid-basic] Basic Pyramid Chart (Population Pyramid)

[MarkusNeusinger]

Description

A pyramid chart displays two opposing horizontal bar charts that share a central axis, creating a pyramid or butterfly shape. Commonly used for population pyramids showing age-gender distributions.

Key Features

• Two bar charts facing opposite directions
• Shared central category axis
• Symmetric or asymmetric comparison
• Categories typically ordered vertically

Applications

• Population pyramids (age by gender)
• Survey responses (agree vs disagree)
• Comparison of two related metrics
• Before/after comparisons

Data Requirements

• category (categorical) - Shared categories (e.g., age groups)
• value_left (numeric) - Values for left side
• value_right (numeric) - Values for right side
• Size: 5-15 categories typical

Visual Elements

• Horizontal bars extending left and right
• Central axis with category labels
• Distinct colors for each side
• Symmetric axis scales (or asymmetric if noted)
• Legend or title identifying each side

[claude]

✅ Spec ID: pyramid-basic

Rationale: Pyramid charts are a distinct visualization type showing two opposing horizontal bars sharing a central axis, commonly used for population demographics.

Add label approved to begin generation.

[github-actions]

✅ Specification Ready: pyramid-basic

PR: #1019

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specification.md

pyramid-basic: Basic Pyramid Chart

Description

A pyramid chart displays two opposing horizontal bar charts that share a central axis, creating a pyramid or butterfly shape. This visualization is ideal for comparing two related metrics across the same categories, revealing asymmetries and patterns in bidirectional data. Most commonly used for population pyramids showing age-gender distributions.

Applications

• Population demographics showing age distribution by gender
• Survey analysis comparing agree vs disagree responses
• Before/after comparisons across categories
• Market research comparing two competing products or segments

Data

• category (categorical) - Shared categories for central axis (e.g., age groups)
• value_left (numeric) - Values for left-extending bars
• value_right (numeric) - Values for right-extending bars
• Size: 5-15 categories typical
• Example: Age groups with male and female population counts

Notes

• Left bars extend from center to the left, right bars extend from center to the right
• Both sides should use symmetric axis scales for fair comparison
• Use distinct colors for each side (e.g., blue/pink for gender)
• Category labels should be placed along the central axis
• Include legend or title identifying what each side represents

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Next: Add approved label to merge this specification to main.

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🤖 spec-create workflow

[github-actions]

🚀 Specification Merged!

Specification: pyramid-basic
PR: #1019 (merged)

The specification is now in main and synced to PostgreSQL.

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Next: Add generate:{library} labels to start generating implementations.

Available libraries: matplotlib, seaborn, plotly, bokeh, altair, plotnine, pygal, highcharts, letsplot

Or use workflow dispatch for bulk operations.

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🤖 spec-create workflow