units (version 1.0-0)

units_options: set one or more units global options

Description

set units global options, mostly related how units are printed and plotted

Usage

units_options(..., sep, group, negative_power, parse, set_units_mode,
  strict_tokenizer, auto_convert_names_to_symbols, simplify, allow_mixed,
  unitless_symbol, define_bel)

Value

in case options are set, invisibly a named list with the option values that are being set; if an option is queried, the current option value.

Arguments

...

named options (character) for which the value is queried

sep

character length two; default c("~", "~"); space separator between variable and units, and space separator between two different units

group

character length two; start and end group, may be two empty strings, a parenthesis pair, or square brackets; default: square brackets.

negative_power

logical, default FALSE; should denominators have negative power, or follow a division symbol?

parse

logical, default TRUE; should the units be made into an expression (so we get subscripts)? Setting to FALSE may be useful if parse fails, e.g. if the unit contains symbols that assume a particular encoding

set_units_mode

character; either "symbols" or "standard"; see set_units; default is "symbols"

strict_tokenizer

logical, default FALSE; non-strict tokenization attaches constants to the following symbol.

auto_convert_names_to_symbols

logical, default TRUE: should names, such as degree_C be converted to their usual symbol?

simplify

logical, default NA; simplify units in expressions?

allow_mixed

logical; if TRUE, combining mixed units creates a mixed_units object, if FALSE it generates an error

unitless_symbol

character; set the symbol to use for unitless (1) units

define_bel

logical; if TRUE, define the unit B (i.e., the bel, widely used with the deci- prefix as dB, decibel) as an alias of lg(re 1). TRUE by default, unless B is already defined in the existing XML database.

Details

This sets or gets units options. Set them by using named arguments, get them by passing the option name.

The default NA value for simplify means units are not simplified in set_units or as_units, but are simplified in arithmetical expressions.

Examples

old = units_options(sep = c("~~~", "~"), group = c("", "")) # more space, parenthesis
old
## set back to defaults:
units_options(sep = c("~", "~"), group = c("[", "]"), negative_power = FALSE, parse = TRUE)
units_options("group")