What is the output of lascatalog processing engine?
The output is a LAS object. Multiple extractions is also possible and is performed the same way by searching the corresponding files and then querying in each file no matter if the region of interest is situated in one or several files. The output becomes list of LAS objects.
What is the purpose of the lascatalog class?
The LAScatalog class and the LAScatalog engine are intricately documented in two dedicated vignettes available here and here. The purpose of this book is to propose alternative documentation with more illustrated examples and real use cases. The function readLAScatalog () reads the header of all the LAS files of a given folder.
How does the lascatalog function in LIDR work?
It expects a templated filename so each written file will be attributed a unique name. In the following example, several LAS files will be written to disk with names like 339348.8_5239254_1.las (center coordinates from each file) and the function returns a LAScatalog object that references all the new files instead of a list of LAS object.
What is the clip ( ) function in lascataglog?
Functions using the clip_* () moniker are a good starting point for exploring the capabilities of the LAScataglog engine. clip_* () functions allow for the extraction of a region of interest (ROI) from a point cloud. The following example extracts a circle from a point cloud loaded into memory in a LAS object:
How to check the name of a LAS file?
In the following example, several LAS files will be written to disk with names like 339348.8_5239254_1.las (center coordinates from each file) and the function returns a LAScatalog object that references all the new files instead of a list of LAS object. We can check the files that were written on disk and see that the names match the template.
What is the Las check function in lascatalog?
The las_check () function performs an inspection of LAScatalog objects for file consistency. For a deep (and longer) inspection of each file use deep = TRUE. This will sequentially load each file entirely.