[marimekko-basic] Basic Marimekko Chart (Mosaic Plot)

[MarkusNeusinger]

Description

A Marimekko chart (also called mekko or mosaic plot) is a stacked bar chart where both width and height of segments represent data values. It shows two categorical dimensions simultaneously with proportional areas.

Key Features

• Bar widths represent one dimension (e.g., market size)
• Segment heights represent another dimension (e.g., share)
• Area proportional to two-way value
• Shows both composition and relative sizes

Applications

• Market share across segments of different sizes
• Product mix by customer segment
• Revenue breakdown by region and product
• Cross-tabulation visualization

Data Requirements

• x_category (categorical) - Categories for bar widths
• y_category (categorical) - Categories within each bar
• value (numeric) - Values determining segment sizes
• Size: 3-7 x-categories, 2-5 y-categories typical

Visual Elements

• Variable-width columns
• Stacked segments within each column
• Column width proportional to total value
• Segment height proportional to share
• Color coding for y-categories
• Legend identifying segments

[claude]

✅ Spec ID: marimekko-basic

Rationale: A Marimekko chart (mosaic plot) is a distinct plot type showing two categorical dimensions with proportional areas - bar widths and segment heights both encode values. No existing spec covers this visualization.

Add label approved to begin generation.

[github-actions]

✅ Specification Ready: marimekko-basic

PR: #1021

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specification.md

marimekko-basic: Basic Marimekko Chart

Description

A Marimekko chart (also called mekko or mosaic plot) is a stacked bar chart where both the width and height of segments represent data values. This visualization shows two categorical dimensions simultaneously with proportional areas, making it ideal for understanding how parts relate to wholes across categories of different sizes.

Applications

• Market share analysis across segments of varying market sizes
• Product mix visualization by customer segment or region
• Revenue breakdown by region and product line
• Cross-tabulation data where both dimensions matter equally

Data

• x_category (categorical) - Categories determining bar widths (e.g., market segments, regions)
• y_category (categorical) - Categories within each bar for stacking (e.g., products, brands)
• value (numeric) - Values determining segment sizes; bar width proportional to column total, segment height proportional to share within column
• Size: 3-7 x-categories, 2-5 y-categories typical for readability
• Example: Market share data with regions as x-categories and product lines as y-categories

Notes

• Bar widths should be proportional to the total value of each x-category
• Segment heights within each bar show the proportion of each y-category
• Area of each segment represents the actual value (width x height proportion)
• Color coding should distinguish y-categories clearly with a legend
• Consider adding value labels on larger segments for readability
• X-axis can show category names centered under each variable-width bar

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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: marimekko-basic
PR: #1021 (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