Examples¶

The examples/ directory contains runnable Python and JSON examples.

examples/trim_migration.py demonstrates a synthetic canonical total 1.2 m/billet and its unchanged physical results. The runnable historical examples in examples/ retain front_scrap_m deliberately as legacy inputs; do not blindly rename that field, especially for p=2. See trim topology and migration.

The current Getting Started and JSON API examples use canonical inputs. All example values are synthetic; substitute your own measured data when needed.

Minimal press from nominal size¶

from pyextrusion import Press

press = Press(
    name="Example 8-inch press",
    nominal_size_in=8,
    table_length_m=54,
)

Explicit press dimensions (synthetic)¶

press = Press(
    name="Example 9-inch press",
    nominal_size_in=9,
    billet_diameter_mm=228,
    container_diameter_mm=236,
    billet_min_length_mm=500,
    billet_max_length_mm=1300,
    table_length_m=64,
    dead_time_sec=14,
    target_net_productivity_kg_h=2200,
)

No billet saw loss¶

from pyextrusion import SawSpec

press = Press(
    name="Press with billet shear",
    nominal_size_in=8,
    table_length_m=54,
    saws=SawSpec(billet_mm=0, puller_mm=5, final_mm=5),
)

Manual butt override¶

adjusted = case.with_production(butt_mm=25)  # Physical thickness in the container.

Without an override, PyExtrusion uses 15 mm for solid/plate and 20 mm for hollow/tubular.

Do not convert these values to incoming-billet length before calling the engine. Inspect result.billet.butt_mass_kg, result.billet.butt_equivalent_billet_mm and result.billet.mass_coefficient_source to trace the conversion. A measured billet_kg_per_mm_override affects the incoming-billet equivalent and upstream billet saw, but the physical butt mass still uses the container section and density.

Compare presses¶

from pyextrusion import compare_presses

comparison = compare_presses([press_8, press_9], case)
for result in comparison.results:
    print(result.press_name, result.real_net_kg_h, result.productivity_index)

The productivity index is orientative; the final industrial decision remains with the user.

Operational planning¶

examples/planning.py shows three day-to-day planning questions using the same profile/case:

produce 300 bars;
extrude exactly 20 billets;
calculate the capacity of a two-hour press window.

Run it with:

python examples/planning.py

Production sequence¶

examples/production_sequence.py calculates three user-supplied orders in sequence, preserves their order and optionally derives theoretical clock timestamps from a supplied datetime.

python examples/production_sequence.py

Multi-press comparison¶

python examples/multi_press_comparison.py

This example applies one process, one planning request and one complete order sequence to several presses without ranking or allocating work.

Engineering screening¶

The Engineering API example provides a complete, runnable chain from modified Feltham mean strain rate through Zener-Hollomon, flow stress, pressure and F_baseline. It also keeps the Stüwe, Saha and interface-temperature calls separate so their different boundaries remain visible.

Production economics¶

The Economics API example calculates recurring production cost, material and scrap effects, first-run tooling/development cost and sales margin from explicit assumptions.