Convert LAZ files to WOLF numpy grids
--------------------------------------

.. attention::
    This tutorial requires version 2.2.40 or later of wolfhece package.

LAZ files contain point clouds and attributes. These files can be large and are not well suited for processing small or localized arrays.

The Wolf Grid format offers a good alternative for storing and manipulating such data. It uses binary numpy arrays, which can be loaded into memory quickly.

While this format may not be the most compact, it is easy to use and share.

`Full example <../_static/laz/convert_laz2wolfgrid.py>`_ :

.. code-block:: python

    from pathlib import Path
    import numpy as np

    from wolfhece.lazviewer.laz_viewer import xyz_laz_grids
    from wolfhece.pydownloader import toys_dataset

    laz1:Path
    laz2:Path

    # Download two LAZ files from the toys dataset
    laz1 = toys_dataset('LAZ', '251500_140750.laz')
    laz2 = toys_dataset('LAZ', '251500_141000.laz')

    # Create a directory to store the numpy grids
    laz_dir = laz1.parent
    np_dir = laz_dir.parent / 'Grids_Numpy'
    np_dir.mkdir(exist_ok= True)

    # Create the grids from the LAZ files
    grids = xyz_laz_grids(dir_grids= np_dir, create= True)

    grids.create_from_laz(dir_laz= laz_dir,          # Path or str to the directory containing the LAZ files
                          ds = 50.,                  # Grid step in the units of the LAZ files (here meters)
                          force_format= np.float32)  # Force the numpy array format (default is np.float64) --> can save disk space

.. note::
    Alternatively, if data are already processed you can download
    an existing grid from a public website using the toy dataset function
    or `laz_grid_from_url` function.

    Data will be downloaded in the 'data' directory of wolfhece package.

.. code-block:: python

    from wolfhece.pydownloader import toys_laz_grid
    grid_dir = toys_laz_grid('LAZ_Numpy', 'example.txt')