eiko 0.9.0

% 1. Setup grid parameters.
N = 101;            % Number of grid points (NxN grid)
dx = 0.001;         % Grid spacing in meters (1 mm, for example)
c = 1540;           % Speed of sound in m/s (uniform medium)

% 2. Create the slowness map (1/velocity).
f = ones(N, N, 'single', 'gpuArray') / c;

% 3. Initialize the time-of-flight field.
u_init = inf(N, N, 'single', 'gpuArray'); % Unknown points set to infinity.

% Set a point source at the center of the grid to time = 0.
center_idx = ceil(N/2);
u_init(center_idx, center_idx) = 0;

% 4. Compute the numerical solution using eiko.
u = eiko(u_init, f, dx);

% 5. Visualize the result.
% Create physical coordinate axes in millimeters using dx
axis_mm = ((1:N) - center_idx) * dx * 1000;

% Set up plot.
figure;
imagesc(axis_mm, axis_mm, u * 1e6);
axis image;

% Format axes and text size.
title('Time-of-Flight', 'FontSize', 14, 'FontWeight', 'bold');
xlabel('x (mm)', 'FontSize', 12, 'FontWeight', 'bold');
ylabel('y (mm)', 'FontSize', 12, 'FontWeight', 'bold');

% Format colorbar.
cb = colorbar;
cb.Label.String = 'Time (\mus)';
cb.Label.FontSize = 12;

The result should look something like this:

For 3D inputs, use eiko3d.

import torch
import matplotlib.pyplot as plt
from eiko import eiko

# 1. Setup device and grid parameters.
device = torch.device("cuda")
N = 101
dx = 0.001  # Grid spacing in meters (1 mm)
c = 1540.0  # Speed of sound in m/s (uniform medium)

# 2. Create the slowness map (1/velocity) on the device.
f = torch.full((N, N), 1.0 / c, dtype=torch.float32, device=device)

# 3. Initialize the time-of-flight field.
# Unknown points are set to infinity
u_init = torch.full((N, N), float('inf'), dtype=torch.float32, device=device)

# Set a point source at the center of the grid to time = 0.
center_idx = N // 2
u_init[center_idx, center_idx] = 0.0

# 4. Compute the numerical solution.
u = eiko(u_init, f, dx=dx)

# 5. Visualize the result.

# Create physical coordinate axes in millimeters using dx
axis_mm = (torch.arange(N) - center_idx) * dx * 1000

# Set up plot (equivalent to 'figure')
plt.figure(figsize=(6, 6))

# 'imagesc' equivalent with physical extents. 
# 'extent' maps the data coordinates to the axes.
extent = [axis_mm[0], axis_mm[-1], axis_mm[0], axis_mm[-1]]
plt.imshow(u.cpu() * 1e6, extent=extent, origin='lower', cmap='viridis')

# 'axis image' equivalent (forces equal pixel aspect ratio)
plt.gca().set_aspect('equal', adjustable='box')

# Format axes and text size
plt.title('Time-of-Flight', fontsize=14, fontweight='bold')
plt.xlabel('x (mm)', fontsize=12, fontweight='bold')
plt.ylabel('y (mm)', fontsize=12, fontweight='bold')

# Format colorbar
cb = plt.colorbar()
cb.set_label(r'Time ($\mu$s)', fontsize=12)

# Display the plot
plt.show()

The result should look something like this:

For 3D inputs, use from eiko import eiko3d.