File Writer

This module provides utility functions to export satellite trajectory data (either in 2D or 3D) to text files.

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def write_to_file_2d(file_name, traj):
    with open(file_name, 'w') as file:
        for (t, r, theta) in zip(traj[:, 0], traj[:, 1], traj[:, 2]):
            file.write(f"{t} {r} {theta}\n")
    print(f"Wrote {traj.shape[0]} points to {file_name}")

• Purpose: Writes a 2D satellite trajectory to a text file, with each row containing time, radius, and angle values.

• Parameters:

  • file_name: Name of the output file.

  • traj: NumPy array of shape (N, 3) containing [t, r, θ] values.

• Implementation:

  • Opens the file for writing.

  • Iterates over trajectory entries and writes each row to file.

  • Each line format: t r θ

• Output: Saves a text file and prints the number of points written.

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def write_to_file_3d(file_name, traj):
    with open(file_name, 'w') as file:
        for (t, r, theta, phi) in 
        zip(traj[:, 0], traj[:, 1], traj[:, 2], traj[:, 3]):
            file.write(f"{t} {r} {theta} {phi}\n")
    print(f"Wrote {traj.shape[0]} points to {file_name}")

• Purpose: Writes a 3D satellite trajectory to a text file, with each row containing time, radius, azimuthal angle, and polar angle.

• Parameters:

  • file_name: Name of the output file.

  • traj: NumPy array of shape (N, 4) containing [t, r, θ, φ] values.

• Implementation:

  • Similar to the 2D function, but includes the additional φ (polar angle) column.

  • Each line format: t r θ φ.

• Output: Saves a text file and prints the number of points written.