[contour-map-geographic] Contour Lines on Map

[MarkusNeusinger]

Description

A map with contour lines (isolines) showing continuous spatial data like elevation, temperature, or pressure on a geographic background.

Applications

• Topographic elevation maps
• Weather pressure systems
• Temperature distribution
• Pollution concentration mapping

Data

• lat, lon (numeric) - Grid coordinates
• value (numeric) - Continuous variable (elevation, temperature, etc.)
• Grid: regular lat/lon grid

Notes

• Smooth contour lines at regular intervals
• Label contour lines with values
• Optional filled contours (choropleth-like)
• Overlay on base map
• Appropriate colormap for data type

[claude]

✅ Spec ID: contour-map-geographic

Rationale: Combines contour visualization (isolines) with geographic mapping - distinct from contour-basic (mathematical x/y grid) and choropleth-basic (discrete region coloring).

Add label approved to begin generation.

[github-actions]

✅ Specification Ready: contour-map-geographic

PR: #3781

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specification.md

contour-map-geographic: Contour Lines on Geographic Map

Description

A contour map overlays isolines (lines of equal value) onto a geographic basemap, visualizing continuous spatial data such as elevation, temperature, or atmospheric pressure across real-world coordinates. Unlike basic contour plots that use abstract x/y coordinates, this plot anchors contours to latitude/longitude positions with geographic context like coastlines, borders, or terrain. It combines the precision of isoline visualization with spatial awareness, making it ideal for meteorological, topographic, and environmental applications.

Applications

• Topographic elevation maps showing terrain contours with labeled heights
• Weather maps displaying pressure systems (isobars) or temperature gradients (isotherms)
• Environmental monitoring showing pollution concentration or radiation levels across a region
• Oceanographic charts displaying water temperature or salinity isolines

Data

• lat (numeric) - Latitude coordinates forming a regular grid (-90 to 90)
• lon (numeric) - Longitude coordinates forming a regular grid (-180 to 180)
• value (numeric) - Continuous variable at each grid point (elevation, temperature, pressure, etc.)
• Size: Grid of 20x20 to 100x100 points covering the geographic region of interest
• Example: Gridded elevation data, weather model output, or interpolated sensor measurements

Notes

• Overlay smooth contour lines on a geographic basemap (coastlines, borders, or terrain)
• Label contour lines with values at appropriate intervals
• Support both line-only contours and optional filled contours between levels
• Use colormap appropriate to data type (terrain colors for elevation, temperature scales for weather)
• Include a colorbar legend showing the value range
• Ensure contour intervals are meaningful for the data (e.g., 100m for elevation, 4mb for pressure)

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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: contour-map-geographic
PR: #3781 (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