pygimli

name: pygimli description: | Multi-method geophysical modelling and inversion framework. Use when Claude needs to: (1) Perform electrical resistivity tomography (ERT) inversion, (2) Run seismic refraction tomography (SRT), (3) Model induced polarization (IP) data, (4) Simulate ground penetrating radar (GPR), (5) Create finite element meshes for geophysical problems, (6) Perform joint inversions of multiple datasets, (7) Forward model geophysical responses, (8) Analyze time-lapse monitoring data. version: 1.0.0 author: Geoscience Skills license: MIT tags: [Geophysical Inversion, ERT, Seismic Refraction, IP, Near-Surface, FEM] dependencies: [pygimli>=1.4.0, numpy, matplotlib] complements: [simpeg, verde, pyvista] workflow_role: modelling

pyGIMLi - Geophysical Inversion

Quick Reference

import pygimli as pg
from pygimli.physics import ert, srt

# Load ERT data
data = ert.load("survey.ohm")

# Invert
mgr = ert.ERTManager(data)
model = mgr.invert(lam=20, verbose=True)

# View result
mgr.showResult()

Key Classes

Essential Operations

Load and View ERT Data

import pygimli as pg
from pygimli.physics import ert

data = ert.load("survey.ohm")
print(f"Measurements: {data.size()}")
ert.showData(data)  # Pseudosection

ERT Inversion

from pygimli.physics import ert

mgr = ert.ERTManager(data)
model = mgr.invert(
    lam=20,          # Regularization
    verbose=True
)
mgr.showResult()
resistivity = mgr.model

Seismic Refraction

from pygimli.physics import srt

data = srt.load("traveltimes.sgt")
mgr = srt.SRTManager(data)
model = mgr.invert(lam=30, zWeight=0.3)
mgr.showResult()

Create Custom Mesh

import pygimli as pg
from pygimli.physics import ert

data = ert.load("survey.ohm")
mesh = pg.meshtools.createParaMesh(
    data.sensors(),
    quality=34.0,
    paraMaxCellSize=5,
    boundary=2
)
pg.show(mesh)

Save and Export

# Save mesh and model
mgr.mesh.save("result_mesh.bms")
pg.save(model, "resistivity_model.vector")

# Export to VTK for ParaView
mgr.mesh.exportVTK("result", mgr.model)

Array Types

Data Formats

When to Use vs Alternatives

Choose pyGIMLi when: You need near-surface geophysical inversion (ERT, SRT, IP) with minimal code. Its manager classes (ERTManager, SRTManager) handle the full workflow from data loading to inversion to visualization in a few lines.

Avoid pyGIMLi when: You need methods beyond near-surface (use SimPEG), or you require a commercial-grade reporting pipeline.

Common Workflows

ERT data inversion and visualization

• Load ERT data file with ert.load("survey.ohm")
• Inspect data: check measurement count with data.size(), plot pseudosection
• Remove outliers or bad data points
• Create ERTManager with data
• Run inversion: mgr.invert(lam=20) (start with higher lambda)
• Check chi-squared value (target ~ 1)
• Visualize result with mgr.showResult()
• Export mesh and model to VTK for ParaView: mgr.mesh.exportVTK()
• Adjust lambda and zWeight if needed, re-invert

Inversion Tips

1. Start with higher lambda (50-100) and decrease
2. Check data quality - remove outliers before inversion
3. Use zWeight < 1 for layered structures
4. Check coverage - low coverage = poorly resolved
5. Chi-squared ~ 1 indicates good fit without overfitting

References

• Geophysical Methods - Supported methods and workflows
• Mesh Generation - Mesh creation and quality control

Scripts

• scripts/ert_inversion.py - Complete ERT inversion workflow