Lookup an SI prefix by name, by exponent (power of 10), or by value. For exponents or values, the best SI prefix is returned.
si_prefix(x) # S3 method for character si_prefix(x) # S3 method for integer si_prefix(x) # S3 method for numeric si_prefix(x)
A named character vector where values are the SI prefix exponents
and names are the SI prefix names, from SI_PREFIXES.
character: x are the names of the prefixes. The prefix
mu can be referred to with its unicode value, "\u03BC", or "mu".
Empty or missing values map to no strings. Invalid values return NA.
integer: x are the exponents of the SI prefixes,
\(-24, -21, ..., -3, 0, 3, ..., 21, 24\).
numeric: x are numeric values.
# lookup by name si_prefix(c("k", "T", "mu", "\u03BC", "", NA))#> k T μ μ #> 3 12 -6 -6 0 0# lookup by exponent with integers si_prefix(c(-2L, -1L, 0L, 5L))#> m m k #> -3 -3 0 3# lookup by value with numeric vectors si_prefix(c(-1100, 5, 1.5e8))#> k M #> 3 0 6