readLAScatalog {lidR} | R Documentation |
Create an object of class LAScatalog
Description
Create an object of class LAScatalog from a folder
or a collection of filenames. A LAScatalog is a representation of a collection
of las/laz files. A computer cannot load all the data at once. A LAScatalog
is a simple way to manage all the files sequentially. Most functions from
lidR
can be used seamlessly with a LAScatalog using the internal
LAScatalog
processing engine. To take advantage of the LAScatalog
processing engine the user must first adjust some processing options using the
appropriate functions. Careful reading of the
LAScatalog class documentation is required to use the
LAScatalog
class correctly.
readLAScatalog
is the original function and always works. Using one of the read*LAScatalog
functions
adds information to the returned object to register a point-cloud type. Registering the correct point
type may improve the performance of some functions by enabling users to select an appropriate spatial index.
See spatial indexing. Notice that by legacy and for backwards-compatibility
reasons readLAScatalog()
and readALSLAScatalog()
are equivalent because lidR was originally designed
for ALS and thus the original function readLAScatalog()
was (supposedly) used for ALS.
Usage
readLAScatalog(
folder,
progress = TRUE,
select = "*",
filter = "",
chunk_size = 0,
chunk_buffer = 30,
...
)
readALSLAScatalog(folder, ...)
readTLSLAScatalog(folder, ...)
readUAVLAScatalog(folder, ...)
readDAPLAScatalog(folder, ...)
catalog(folder, ...)
Arguments
folder |
string. The path of a folder containing a set of las/laz files. Can also be a vector of file paths. |
progress , select , filter , chunk_size , chunk_buffer |
Easily accessible processing options tuning. See LAScatalog-class and engine_options. |
... |
Extra parameters to list.files. Typically
|
Value
A LAScatalog
object
Examples
# A single file LAScatalog using data provided with the package
LASfile <- system.file("extdata", "Megaplot.laz", package="lidR")
ctg = readLAScatalog(LASfile)
plot(ctg)
## Not run:
ctg <- readLAScatalog("</path/to/folder/of/las/>")
# Internal engine will sequentially process chunks of size 500 x 500 m
opt_chunk_size(ctg) <- 500
# Internal engine will align the 500 x 500 m chunks on x = 250 and y = 300
opt_alignment(ctg) <- c(250, 300)
# Internal engine will not display a progress estimation
opt_progress(ctg) <- FALSE
# Internal engine will not return results into R.
# Instead it will write results in files.
# Files will be named e.g.
# filename_256000_1.ext
# filename_257000_2.ext
# filename_258000_3.ext
# ...
opt_output_files(ctg) <- "/path/filename_{XBOTTOM}_{ID}"
# More details in the documentation
help("LAScatalog-class", "lidR")
help("engine_options", "lidR")
## End(Not run)