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Set global processing options

Source: R/processor.R
set_exec_options.Rd

Set global processing options for the exec function. By default, pipelines are executed without a progress bar, processing one file at a time sequentially. The following options can be passed to the exec() function in four ways. See details.

Usage

set_exec_options(
  ncores = NULL,
  progress = NULL,
  buffer = NULL,
  chunk = NULL,
  ...
)

unset_exec_option()

Arguments

ncores

An object returned by one of sequential(), concurrent_points(), concurrent_files(), or nested(). See multithreading. If NULL the default is concurrent_points(half_cores()). If a simple integer is provided it corresponds to concurrent_files(ncores).

progress

boolean. Displays a progress bar.

buffer

numeric. Each file is read with a buffer. The default is NULL, which does not mean that the file won't be buffered. It means that the internal routine knows if a buffer is needed and will pick the greatest value between the internal suggestion and this value.

chunk

numeric. By default, the collection of files is processed by file (chunk = NULL or chunk = 0). It is possible to process in arbitrary-sized chunks. This is useful for e.g., processing collections with large files or processing a massive copc file.

...

Other internal options not exposed to users.

Details

There are 4 ways to pass processing options, and it is important to understand the precedence rules:

The first option is by explicitly naming each option. This option is deprecated and used for convenience and backward compatibility.


exec(pipeline, on = f, progress = TRUE, ncores = 8)

The second option is by passing a list to the with argument. This option is more explicit and should be preferred. The with argument takes precedence over the explicit arguments.


exec(pipeline, on = f, with = list(progress = TRUE, chunk = 500))

The third option is by using a LAScatalog from the lidR package. A LAScatalog already carries some processing options that are respected by the lasR package. The options from a LAScatalog take precedence.


exec(pipeline, on = ctg, ncores = 4)

The last option is by setting global processing options. This has global precedence and is mainly intended to provide a way for users to override options if they do not have access to the exec() function. This may happen when a developer creates a function that executes a pipeline internally, and users cannot provide any options.


set_exec_options(progress = TRUE, ncores = concurrent_files(2))
exec(pipeline, on = f)

See also

multithreading