Package 'RcppFastFloat'

Title: 'Rcpp' Bindings for the 'fast_float' Header-Only Library for Number Parsing
Description: Converting ascii text into (floating-point) numeric values is a very common problem. The 'fast_float' header-only C++ library by Daniel Lemire does it very well and very fast at up to or over to 1 gigabyte per second as described in more detail in <doi:10.48550/arXiv2101.11408>. 'fast_float' is licensed under the Apache 2.0 license and provided here for use by other R packages via a simple 'LinkingTo:' statement.
Authors: Dirk Eddelbuettel, Brendan Knapp
Maintainer: Dirk Eddelbuettel <[email protected]>
License: GPL (>= 2)
Version: 0.0.4
Built: 2024-07-06 07:21:20 UTC
Source: https://github.com/eddelbuettel/rcppfastfloat

Help Index


Ultra efficient string-to-double Conversion

Description

For character vectors, as.double2() is a drop-in replacement for base::as.double().

Usage

as.double2(x)

Arguments

x

A vector of type character.

See Also

as.double()

Examples

set.seed(8675309)
input <- sample(c(
  paste0(" \r\n\t\f\v", c(0.0, sqrt(seq(1, 10))), " \r\n\t\f\v"),
  c("NaN", "-NaN", "nan", "-nan",
    "Inf", "-Inf", "inf", "-inf", "infinity", "-infinity",
    NA_character_,
    "  1970-01-01", "1970-01-02  ")
))
input

suppressWarnings(as.double2(input)) # NAs introduced by coercion

comparison <- suppressWarnings(
  matrix(c(as.double(input), as.double2(input)),
         ncol = 2L,
         dimnames = list(NULL, c("as.double()", "as.double2()")))
)
comparison

all.equal(comparison[, "as.double()"], comparison[, "as.double2()"])

Floating Point Parsing Example

Description

This example is adapted from the example of the upstream README.md file, and generalized to be called from R with variable input.

Usage

parseExample(input = "3.1416 xyz ", verbose = TRUE)

Arguments

input

A character variable with text to parse including a simple default

verbose

A boolean variable to show or suppress progress, defaults to true

Value

A floating point scalar is returned on success; in case of parsing failure the function exists via stop().

Examples

parseExample()