harmonica
Gravity and magnetic data processing and forward modelling using Fatiando a Terra. Use when Claude needs to: (1) Compute gravity forward models (point masses, prisms, tesseroids), (2) Apply terrain/Bouguer corrections, (3) Grid scattered potential field data with equivalent sources, (4) Perform upward/downward continuation, (5) Calculate magnetic anomalies from magnetized bodies, (6) Apply derivative filters (gradients, tilt angle), (7) Process regional or local gravity surveys.
npx skills add majiayu000/claude-skill-registry --skill harmonica --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Harmonica - Gravity and Magnetics ## Quick Reference ```python import harmonica as hm import numpy as np # Forward model - prism gravity prism = [-500, 500, -500, 500, -2000, -500] # (west, east, south, north, bottom, top) gravity = hm.prism_gravity(coordinates, prism, density=500, field='g_z') # Terrain correction layer = hm.prism_layer((easting, northing), surface=topo, reference=0, properties={'density': 2670}) terrain_effect = layer.gravity(coordinates, field='g_z') # Equivalent source gridding eqs = hm.EquivalentSources(depth=10000, damping=10) eqs.fit(coordinates, gravity_data) grid = eqs.grid(spacing=5000, data_names=['gravity']) # Upward continuation (requires gridded xarray) upward = hm.upward_continuation(gravity_grid, height_displacement=1000) ``` ## Key Functions | Function | Purpose | |----------|---------| | `point_gravity` | Gravity from point masses | | `prism_gravity` | Gravity from rectangular prisms | | `tesseroid_gravity` | Gravity from spherical prisms (regional/global) | | `prism_magnetic` | Magnetic anomaly from prisms | | `prism_layer` | Create layer of prisms from topography | | `EquivalentSources` | Grid scattered data with equivalent sources | | `upward
- Quick Reference
- Key Functions
- Essential Operations
- Forward Model - Rectangular Prism
- Terrain Correction
- Equivalent Source Gridding
- Magnetic Forward Model
- Derivative Filters
- Coordinate System
- When to Use vs Alternatives
- Common Workflows
- Process Gravity Survey with Terrain Correction and Gridding
- Common Issues
- Tips
What does the harmonica skill do?
Gravity and magnetic data processing and forward modelling using Fatiando a Terra. Use when Claude needs to: (1) Compute gravity forward models (point masses, prisms, tesseroids), (2) Apply terrain/Bouguer corrections, (3) Grid scattered potential field data with equivalent sources, (4) Perform upward/downward continuation, (5) Calculate magnetic anomalies from magnetized bodies, (6) Apply derivative filters (gradients, tilt angle), (7) Process regional or local gravity surveys.
How do I install it?
Run `npx skills add majiayu000/claude-skill-registry --skill harmonica --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From majiayu000/claude-skill-registry, a repository with 534 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.