pyfor.collection

Functions

from_dir

from_dir(las_dir, kwargs = {})

Constructs a CloudDataFrame from a directory of las files.

Parameter	Type	Description
las_dir		The directory of las or .laz files.
glob_str		A glob string to select files from the directory. For example: “*.laz” to select .laz files only.

Returns: A CloudDataFrame constructed from the directory of las files.

Classes

CloudDataFrame

CloudDataFrame(args = (), kwargs = {})

Implements a data frame structure for processing and managing multiple Cloud objects. It is recommended to initialize using the from_dir function.

Attributes

Attribute	Type	Description
n_threads
tiles

Properties

bounding_box

Returns: A tuple (minx, miny, maxx, maxy) of the bounding box for the entire collection.

Methods

par_apply

par_apply(func, by_file = False, args = None)

Apply a function to the collection in parallel. There are two major use cases:

1. Buffered Tiles: In the case of buffered tiles, the func argument should contain a function that takes two arguments, the first being an aggregated cloud.Cloud object, and the second being a shapely.geometry.Polygon that describes the bounding box of the aggregated tile. For this case, set by_file to False (this is the default).

2. Raw Files: In the case of processing raw tiles in parallel, the func argument should contain a function that takes only one argument, the absolute file path to the tile at that iteration. For this case, set by_file to True.

Parameter	Type	Description
func		A function used to process each tile or raw file (see above).
by_file		Forces par_apply to operate on raw files only if True.
args		An optional dictionary of keyword arguments passed to the applying function.

retile_raster

retile_raster(cell_size, target_tile_size, buffer = 0)

A retiling operation that creates raster-compatible sized tiles. Important for creating project-level rasters. Changes self.tiles in place. Note that the target tile size is approximate, and is rounded to the nearest size that is compatible with the defined cell size.

Parameter	Type	Description
cell_size		The target cell size of the output raster.
target_tile_size		The target tile size of the retiling operation.
buffer		The amount to buffer each input tile.

reset_tiles

reset_tiles()

Reset the tiles to describe the bounding boxes of each .las file in place.

grid_spec

grid_spec(cell_size)

A GridSpec that covers the whole collection, snapped to the cell size.

Passing this spec to the processing of every tile is how per tile rasters are made to line up with each other, because every tile then grids its points on the same lattice rather than on its own extent. It is also what a raster trimmed to a tile boundary needs in order for Raster.force_extent to accept that boundary.

Parameter	Type	Description
cell_size		The cell size of the rasters being produced.

Returns: A GridSpec covering the collection.

plot

plot(kwargs = {})

Plots the bounding boxes of the Cloud objects.

Parameter	Type	Description
**kwargs		Keyword arguments to geopandas.GeoDataFrame.plot.

plot_metrics

plot_metrics(heightbreak, index = None)

Retrieves a set of 29 standard metrics, including height percentiles and other summaries. Intended for use on plot-level point clouds.

Parameter	Type	Description
index		An iterable of indices to set as the output dataframe index.

Returns: A pandas dataframe of standard metrics.

Retiler

Retiler(cdf)

Attributes

Attribute	Type	Description
cdf

Methods

retile_raster

retile_raster(target_cell_size, original_tile_size, buffer = 0)

Creates a retiling grid for a specified target cell size. This creates a list of polygons such that if a raster is constructed from a polygon it will exactly fit inside given the specified target cell size. Useful for creating project level rasters.

Parameter	Type	Description
target_cell_size		The desired output cell size
original_tile_size		The original tile size of the project
buffer		The distance to buffer each new tile to prevent edge effects.

Returns: A list of shapely polygons that correspond to the new grid.

retile_buffer

retile_buffer(buffer)

A simple buffering operation.

Returns: A list of buffered shapely polygons.