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Implementing a full scenario

Note

NDK and its examples are under constant development, more information and content will be added to this example soon!

The following code is a simplified implementation of NDK's Scenario 1.

Implementing a Scenario

import numpy as np

from neurotechdevkit import sources
from neurotechdevkit.grid import Grid
from neurotechdevkit.problem import Problem
from neurotechdevkit.results import SteadyStateResult2D
from neurotechdevkit.scenarios import Scenario2D, Target

Creating the scenario

scenario = Scenario2D()
scenario.center_frequency = 5e5  # Hz
scenario.target = Target(
    target_id="target_1", center=[0.064, 0.0], radius=0.004, description=""
)
scenario.material_properties = {}
scenario.origin = [0.0, -0.035]
scenario.sources = [
    sources.FocusedSource2D(
        position=[0.0, 0.0],
        direction=[1.0, 0.0],
        aperture=0.064,
        focal_length=0.064,
        num_points=1000,
    )
]
scenario.material_outline_upsample_factor = 8

Creating grid

grid = Grid.make_grid(
    extent=(0.12, 0.07),  # m
    speed_water=1500,
    center_frequency=scenario.center_frequency,
    ppw=6,
)

scenario.grid = grid

Creating masks

def fill_mask(mask, start, end, dx):
    # fill linearly along the x axis
    if end is None:
        n = int(start / dx)
        mask[n:] = True
    else:
        n = int(start / dx)
        m = int(end / dx)
        mask[n:m] = True


def create_masks(grid):
    # layers are defined by X position
    dx = grid.space.spacing[0]

    layers_m = np.array(
        [
            0.026,  # water
            0.004,  # skin
            0.0015,  # cortical bone
            0.004,  # trabecular bone
            0.001,  # cortical bone
            0.0835,  # brain
        ]
    )
    layers = np.array(
        ["water", "skin", "cortical_bone", "trabecular_bone", "cortical_bone", "brain"]
    )
    interfaces = np.cumsum(layers_m)

    mask_materials = {}

    for material in np.unique(layers):
        mask = np.zeros(grid.space.shape, dtype=bool)
        for index in np.where(layers == material)[0]:
            start = interfaces[index - 1] if material != "water" else 0
            end = interfaces[index] if material != "brain" else None
            fill_mask(mask, start=start, end=end, dx=dx)
        mask_materials[material] = mask
    return mask_materials


scenario.material_masks = create_masks(grid)

Rendering the layout

scenario.render_layout()

Scenario Layout

Creating problem

problem = Problem(grid=grid)
problem.add_material_fields(
    materials=scenario.materials,
    masks=scenario.material_masks,
)
scenario.problem = problem

Rendering the simulation

result = scenario.simulate_steady_state()
assert isinstance(result, SteadyStateResult2D)
result.render_steady_state_amplitudes(show_material_outlines=False)

Steady-State Wave Amplitude

Out:

Estimated time to complete simulation: 47 seconds. Memory required is 8.110059917325207 GB (available 73.624051712 GB). These values are approximated.
/home/circleci/.cache/pypoetry/virtualenvs/neurotechdevkit-3aSsmiER-py3.10/lib/python3.10/site-packages/devito/finite_differences/differentiable.py:224: DeprecationWarning: NotImplemented should not be used in a boolean context
  return super(Differentiable, self).__eq__(other) and\
/home/circleci/.cache/pypoetry/virtualenvs/neurotechdevkit-3aSsmiER-py3.10/lib/python3.10/site-packages/devito/finite_differences/differentiable.py:224: DeprecationWarning: NotImplemented should not be used in a boolean context
  return super(Differentiable, self).__eq__(other) and\

Total running time of the script: ( 0 minutes 25.588 seconds)

Download Python source code: plot_full_scenario.py

Download Jupyter notebook: plot_full_scenario.ipynb

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