#### NOTE [Go to the end](#sphx-glr-download-auto-examples-readers-writers-plot-convert-trajectory-to-frame-py) to download the full example code. # Extract Trajectory Frame to Data File Take a later entry from a LAMMPS trajectory and save it as a data file. ```Python import os from pathlib import Path from pylimer_tools_cpp import DataFileWriter, UniverseSequence if not os.path.exists("generated_structures"): os.makedirs("generated_structures") ``` For large trajectories, frames are loaded on-demand Load a LAMMPS dump trajectory file (replace with your file) ```Python def _find_fixtures_dir() -> Path: for cur in ( [Path(__file__).resolve().parent] if "__file__" in globals() else [] ) + [Path.cwd()]: for p in [cur] + list(cur.parents): candidate = p / "tests" / "pylimer_tools" / "fixtures" if candidate.is_dir(): return candidate return Path("tests/pylimer_tools/fixtures").resolve() _fixtures_dir = _find_fixtures_dir() file_path = str(_fixtures_dir) sequence = UniverseSequence() sequence.initialize_from_dump_file( initial_data_file=os.path.join(file_path, "big_dump_file_data.out"), dump_file=os.path.join(file_path, "big_dump_file.lammpstrj"), ) # Get the last frame, for example final_universe = sequence.at_index(len(sequence) - 1) # Write as data file writer = DataFileWriter(final_universe) writer.config_include_angles(True) writer.write_to_file("generated_structures/final_configuration.data") ``` **Total running time of the script:** (0 minutes 0.079 seconds) [`Download Jupyter notebook: plot_convert_trajectory_to_frame.ipynb`](_downloads/7fd95444cda60585d08d3023ce3b33c4/plot_convert_trajectory_to_frame.ipynb) [`Download Python source code: plot_convert_trajectory_to_frame.py`](_downloads/fc947f7bf2720e718949e810d3870e92/plot_convert_trajectory_to_frame.py) [`Download zipped: plot_convert_trajectory_to_frame.zip`](_downloads/ccddbdb2a31e3b452b8faf71bd78deca/plot_convert_trajectory_to_frame.zip) [Gallery generated by Sphinx-Gallery](https://sphinx-gallery.github.io)