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BEACH

Post-processing Tutorial

This short tutorial shows how to inspect the first run with the CLI and Python. For file meanings, see Reading Output Files. For the full API, see Python Post-processing API Reference.

Inspect a Run with the CLI

Section titled “Inspect a Run with the CLI”
Terminal window
beachx inspect outputs/latest

Save figures:

Terminal window
beachx inspect outputs/latest \
  --save-bar outputs/latest/charges_bar.png \
  --save-mesh outputs/latest/charges_mesh.png \
  --save-potential-mesh outputs/latest/potential_mesh.png

For sim.field_bc_mode="periodic2", draw the mesh wrapped into the periodic cell:

Terminal window
beachx inspect outputs/latest \
  --save-mesh outputs/latest/charges_mesh_periodic.png \
  --apply-periodic2-mesh

Make a History Animation

Section titled “Make a History Animation”

When charge_history.csv exists:

Terminal window
beachx animate outputs/latest \
  --quantity charge \
  --save-gif outputs/latest/charge_history.gif \
  --total-frames 200

If potential_history.csv is enabled, use --quantity potential as well.

Read Results from Python

Section titled “Read Results from Python”
from beach import Beach


b = Beach("outputs/latest")
print("absorbed:", b.result.absorbed)
print("escaped:", b.result.escaped)
print("batches:", b.result.batches)


b.plot_bar()
b.plot_mesh()
b.plot_potential()

If the config file is not near the output directory, pass it explicitly.

b = Beach("outputs/latest", config_path="beach.toml")

Select a Mesh

Section titled “Select a Mesh”

Use mesh_sources.csv to find mesh_id, then select the target mesh.

from beach import Beach


b = Beach("outputs/latest")
mesh1 = b.get_mesh(1)
charge1 = b.get_mesh_charge(1)
print(mesh1.centers.shape, charge1.shape)

When history exists, pass a batch index.

mesh1_step10 = b.get_mesh(1, step=10)
charge1_step10 = b.get_mesh_charge(1, step=10)

Slices, Forces, and Mobility

Section titled “Slices, Forces, and Mobility”

For more advanced analysis, start with these CLI commands.

Terminal window
beachx slices outputs/latest \
  --grid-n 200 \
  --save outputs/latest/potential_slices.png


beachx coulomb outputs/latest \
  --component z \
  --save outputs/latest/coulomb_force_z.png


beachx mobility outputs/latest \
  --density-kg-m3 2500 \
  --mu-static 0.4 \
  --save-csv outputs/latest/mobility_summary.csv

These commands resolve geometry and periodic2 settings from nearby beach.toml. If no config is found, pass the corresponding --config option.