spec: add scatter-size-mapped specification

Author: MarkusNeusinger

plots/scatter-size-mapped/specification.md

@@ -0,0 +1,39 @@
+# scatter-size-mapped: Bubble Chart
+
+## Description
+
+A bubble chart where marker size represents a third variable. Semi-transparent markers reveal overlapping points and enable comparison of three dimensions simultaneously on a 2D plane.
+
+## Applications
+
+- **Economic analysis**: Comparing countries by GDP, population, and area
+- **Business metrics**: Visualizing market segments by revenue, growth, and market share
+- **Scientific data**: Showing measurements with intensity or magnitude values
+- **Social sciences**: Displaying demographic data across multiple variables
+
+## Data
+
+Generate synthetic data representing country economic indicators:
+- 30-50 data points representing different entities
+- X-axis: GDP per capita (continuous, 1,000-80,000 range)
+- Y-axis: Life expectancy (continuous, 50-85 range)
+- Bubble size: Population (log scale recommended for better visibility)
+- Optional: Category for coloring by region/continent
+
+Example structure:
+```
+country      | gdp_per_capita | life_expectancy | population  | region
+USA          | 63000          | 78.5           | 330000000   | Americas
+Germany      | 51000          | 81.2           | 83000000    | Europe
+Japan        | 42000          | 84.3           | 126000000   | Asia
+```
+
+## Notes
+
+- Use semi-transparent markers (alpha 0.5-0.7) to reveal overlapping bubbles
+- Scale bubble sizes appropriately - largest should not overwhelm the plot
+- Consider log scaling for size variable if data spans multiple orders of magnitude
+- Include size legend showing what bubble sizes represent
+- Add axis labels with units
+- Use colormap if including category dimension
+- Consider adding annotations for notable data points

plots/scatter-size-mapped/specification.yaml

@@ -0,0 +1,11 @@
+spec_id: scatter-size-mapped
+title: Bubble Chart
+created: 2025-12-27T19:20:00Z
+updated: 2025-12-27T19:20:00Z
+issue: 2375
+suggested: null
+tags:
+  plot_type: [scatter, bubble, size-mapped]
+  domain: [economics, business, general]
+  features: [multivariate, 2d, size-encoding]
+  data_type: [numeric, continuous]