Animated 2D trajectories

An animation to show 2D trajectory customization.

import time

import joblib
import matplotlib.pyplot as plt
import numpy as np
import tempfile as tmp
from PIL import Image, ImageSequence

import mrinufft.trajectories.display as mtd
import mrinufft.trajectories.trajectory2D as mtt
from mrinufft.trajectories.display import displayConfig

Script options

Nc = 16
Ns = 200
nb_repetitions = 8

one_shot = 0
figsize = 4

nb_frames = 3
duration = 150  # seconds

Trajectory generation

# Initialize trajectory function
functions = [
    # Radial
    ("Radial", lambda x: mtt.initialize_2D_radial(x, Ns)),
    ("Radial", lambda x: mtt.initialize_2D_radial(Nc, Ns, tilt=x)),
    (
        "Radial",
        lambda x: mtt.initialize_2D_radial(Nc, Ns, tilt=(1 + x) * np.pi / Nc, in_out=x),
    ),
    ("Radial", lambda x: mtt.initialize_2D_radial(Nc, Ns, tilt=x)),
    ("Radial", lambda x: mtt.initialize_2D_radial(Nc, Ns, tilt="uniform")),
    # Spiral
    ("Spiral", lambda x: mtt.initialize_2D_spiral(Nc, Ns, nb_revolutions=x)),
    ("Spiral", lambda x: mtt.initialize_2D_spiral(Nc, Ns, spiral=x)),
    ("Spiral", lambda x: mtt.initialize_2D_spiral(Nc, Ns, spiral=x)),
    ("Spiral", lambda x: mtt.initialize_2D_spiral(Nc, Ns, nb_revolutions=x)),
    ("Spiral", lambda x: mtt.initialize_2D_spiral(Nc, Ns, nb_revolutions=x)),
    ("Spiral", lambda x: mtt.initialize_2D_spiral(Nc, Ns, nb_revolutions=1e-5)),
    # Cones
    ("Cones", lambda x: mtt.initialize_2D_cones(Nc, Ns, nb_zigzags=x)),
    ("Cones", lambda x: mtt.initialize_2D_cones(Nc, Ns, width=x)),
    ("Cones", lambda x: mtt.initialize_2D_cones(Nc, Ns, width=x)),
    ("Cones", lambda x: mtt.initialize_2D_cones(Nc, Ns, width=0)),
    # Sinusoids
    (
        "Sinusoids",
        lambda x: mtt.initialize_2D_sinusoide(Nc, Ns, nb_zigzags=3 * x, width=x),
    ),
    (
        "Sinusoids",
        lambda x: mtt.initialize_2D_sinusoide(Nc, Ns, nb_zigzags=3 * x, width=x),
    ),
    ("Sinusoids", lambda x: mtt.initialize_2D_sinusoide(Nc, Ns, nb_zigzags=0, width=0)),
    # Rings
    ("Rings", lambda x: mtt.initialize_2D_rings(x, Ns, nb_rings=x)[::-1]),
    ("Rings", lambda x: mtt.initialize_2D_rings(x, Ns, nb_rings=nb_repetitions)[::-1]),
    ("Rings", lambda x: mtt.initialize_2D_rings(Nc, Ns, nb_rings=nb_repetitions)[::-1]),
    # Rosette
    ("Rosette", lambda x: mtt.initialize_2D_rosette(Nc, Ns, coprime_index=x)),
    ("Rosette", lambda x: mtt.initialize_2D_rosette(Nc, Ns, coprime_index=30)),
    # Waves
    ("Waves", lambda x: mtt.initialize_2D_waves(Nc, Ns, nb_zigzags=6 * x, width=x)),
    ("Waves", lambda x: mtt.initialize_2D_waves(Nc, Ns, nb_zigzags=6 * x, width=x)),
    ("Waves", lambda x: mtt.initialize_2D_waves(Nc, Ns, nb_zigzags=6, width=1)),
    # Lissajous
    ("Lissajous", lambda x: mtt.initialize_2D_lissajous(Nc, Ns, density=x)),
    ("Lissajous", lambda x: mtt.initialize_2D_lissajous(Nc, Ns, density=10)),
]

# Initialize trajectory arguments
arguments = [
    # Radial
    np.around(np.linspace(1, Nc, 4 * nb_frames)).astype(int),  # Nc
    np.linspace(2 * np.pi / Nc, np.pi / Nc, 2 * nb_frames),  # tilt
    np.around(np.sin(np.linspace(0, 2 * np.pi, 2 * nb_frames))).astype(bool),  # in_out
    np.linspace(np.pi / Nc, 2 * np.pi / Nc, 2 * nb_frames),  # tilt
    [None] * nb_frames,  # None
    # Spiral
    np.linspace(1e-5, 1, 2 * nb_frames),  # nb_revolutions
    np.linspace(1, np.sqrt(1 / 3), 2 * nb_frames) ** 2,  # spiral
    np.linspace(1 / 3, 1, 2 * nb_frames),  # spiral
    np.linspace(1, 3, 2 * nb_frames),  # nb_revolutions
    np.linspace(3, 1e-5, 4 * nb_frames),  # nb_revolutions
    [None] * nb_frames,  # None
    # Cones
    np.linspace(0, 5, 2 * nb_frames),  # nb_zigzags
    np.linspace(1, 2, nb_frames),  # width
    np.linspace(2, 0, 2 * nb_frames),  # width
    [None] * nb_frames,  # None
    # Sinusoids
    np.linspace(0, 1, 2 * nb_frames),  # width & nb_zigzags
    np.linspace(1, 0, 2 * nb_frames),  # width & nb_zigzags
    [None] * nb_frames,  # None
    # Rings
    np.around(np.linspace(1, nb_repetitions, 4 * nb_frames)).astype(
        int
    ),  # Nc & nb_rings
    np.around(np.linspace(nb_repetitions, Nc, 2 * nb_frames)).astype(int),  # Nc
    [None] * nb_frames,  # None
    # Rosette
    np.around(np.linspace(0, np.sqrt(30), 6 * nb_frames) ** 2).astype(
        int
    ),  # coprime_index
    [None] * nb_frames,  # None
    # Waves
    np.linspace(0, 2, 4 * nb_frames),  # width & nb_zigzags
    np.linspace(2, 1, 2 * nb_frames),  # width & nb_zigzags
    [None] * nb_frames,  # None
    # Lissajous
    np.linspace(1, 10, 6 * nb_frames),  # density
    [None] * nb_frames,  # None
]

Animation rendering

frame_setup = [
    (f, i, name, arg)
    for (name, f), args in list(zip(functions, arguments))
    for i, arg in enumerate(args)
]


def draw_frame(func, index, name, arg):
    """Draw a single frame of the gif and save it to a tmp file."""
    trajectory = func(arg)
    # General configuration
    fig = plt.figure(figsize=(2 * figsize, figsize))
    subfigs = fig.subfigures(1, 2, wspace=0)

    # Trajectory display
    subfigs[0].suptitle(name, fontsize=displayConfig.fontsize, x=0.5, y=0.98)
    ax = mtd.display_2D_trajectory(
        trajectory, one_shot=one_shot, figsize=figsize, subfigure=subfigs[0]
    )
    ax.set_aspect("equal")

    # Gradient display
    subfigs[1].suptitle("Gradients", fontsize=displayConfig.fontsize, x=0.5, y=0.98)
    mtd.display_gradients_simply(
        trajectory,
        shot_ids=[one_shot],
        figsize=figsize,
        subfigure=subfigs[1],
        uni_gradient="k",
        uni_signal="gray",
    )

    # Save figure
    filename = f"{tmp.NamedTemporaryFile().name}.png"
    plt.savefig(filename, bbox_inches="tight")
    plt.close()
    return filename


image_files = joblib.Parallel(n_jobs=1)(
    joblib.delayed(draw_frame)(*data) for data in frame_setup
)


# Make a GIF of all images.
imgs = [Image.open(img) for img in image_files]
imgs[0].save(
    "mrinufft_2D_traj.gif",
    save_all=True,
    append_images=imgs[1:],
    optimize=False,
    duration=duration,
    loop=0,
)



# sphinx_gallery_thumbnail_path = 'generated/autoexamples/images/mrinufft_2D_traj.gif'