Accurate distance calculation

Skill cxcscmu/SkillLearnBench/skills/b1-one-shot-gemini-3-flash-preview/earthquake-plate-calculation/accurate-distance-calculation

Using map projections to calculate real-world distances in meters or kilometers accurately.From its SKILL.md

Install

npx -y skills add cxcscmu/SkillLearnBench --skill accurate-distance-calculation

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

SKILL.md

1.1 KB, 258 tokens by cl100k_base, as published. Nobody here has run it

Accurate Distance Calculation

Overview

Calculating distances in degrees (EPSG:4326) is incorrect because degrees represent different distances depending on the latitude. Always project to a metric system.

Choosing a Projection

EPSG:4087: World Equidistant Cylindrical (Good for global distance approximation).
UTM: Universal Transverse Mercator (Best for local, high-accuracy areas).

Conversion and Calculation

# Project to metric (meters)
METRIC_CRS = "EPSG:4087"
gdf_projected = gdf.to_crs(METRIC_CRS)
target_geom_projected = target_gdf.to_crs(METRIC_CRS).geometry.unary_union

# Calculate distance (returns meters)
gdf['distance_meters'] = gdf_projected.distance(target_geom_projected)

# Convert to Kilometers
gdf['distance_km'] = gdf['distance_meters'] / 1000.0

Finding Extremes

# Furthest point
furthest = gdf.nlargest(1, 'distance_km')

# Closest point
closest = gdf.nsmallest(1, 'distance_km')

What ships with it

Read from the repository

Just SKILL.md. No reference files, no scripts.