# Directory `macros/generic/xint`

% README % xint 1.4b % 2020/02/25

Source: xint.dtx 1.4b 2020/02/25 (doc 2020/02/25) Author: Jean-Francois Burnol Info: Expandable operations on big integers, decimals, fractions License: LPPL 1.3c

# Aim and usage

It is possible to use the package both with Plain (`\input xintexpr.sty`

) or with the LaTeX macro format (`\usepackage{xintexpr}`

).

The basic aim is provide *expandable* computations on (arbitrily big) integers, fractions, and floating point numbers (at a user chosen precision). The four operations and the square-root extraction achieve so-called *correct rounding* for the given arbitrary precision.

The syntax knows dummy variables, as in this example:

\xinteval{reduce(add(x/(x+7), x = 1000..1010))}

which expands to:

108959959329292321880648657/9974444716475301992902544

Trigonometrical functions are available:

\xintDigits*:=48\relax

\xintfloateval{[-2] sind(37)}

expands to:

0.6018150231520482799179770004414898414256377098

The -2 means to round the result to 2 digits less than float precision: currently trigonometrical functions are mostly implemented at high level via the user interface for declaring functions and variables and have no way to use guard digits, hence the last two digits are often not accurate.

Release `1.4`

adds support for nested structures. For example:

\xintthealign\xintexpr ndseq(1/(i+j), i=1..5; j=1..5)\relax

will print on the page (this is customizable, e.g. to use a pmatrix environnement rather):

[[ 1/2, 1/3, 1/4, 1/5, 1/6 ], [ 1/3, 1/4, 1/5, 1/6, 1/7 ], [ 1/4, 1/5, 1/6, 1/7, 1/8 ], [ 1/5, 1/6, 1/7, 1/8, 1/9 ], [ 1/6, 1/7, 1/8, 1/9, 1/10 ]]

It is possible to declare "universal functions" (à la NumPy) which will act itemwise on all leaves of such "arrays". More features are planned such as providing an interface to algebra of matrices in this framework.

# Installation

`xint`

is included in TeXLive (hence MacTeX also) and in MikTeX. Thus, use the package manager to update your distribution.

Alternatives:

- download
`xint.tds.zip`

and install in a suitable TDS-compliant repertory via`unzip`

. "admin" privilges might be needed, as well as a file database rebuild (`texhash`

). For example, on macos x, installation into user home folder (no`sudo`

, and no`texhash`

as it is recommended to not have a ls-R file there)

unzip xint.tds.zip -d ~/Library/texmf

- all files can be extracted using
`etex xint.dtx`

, or`make`

if the`Makefile`

included in the CTAN upload is present; see the file`INSTALL`

, if present, else read the help in extracted file`Makefile.mk`

.

# Documentation

`README.md`

: this file

`CHANGES.html`

: change log as relevant to end users (`texdoc --list xint`

)

`xint.pdf`

: user manual

`sourcexint.pdf`

: commented source code (`texdoc --list xint`

or `texdoc sourcexint`

)

# Requirements

Since release `1.4`

, `xintexpr`

requires the `\expanded`

primitive. This is a functionality of all major TeX engines since TeXLive 2019.

# License

Copyright (C) 2013-2020 by Jean-Francois Burnol

This Work may be distributed and/or modified under the conditions of the LaTeX Project Public License version 1.3c. This version of this license is in

http://www.latex-project.org/lppl/lppl-1-3c.txt

and version 1.3 or later is part of all distributions of LaTeX version 2005/12/01 or later.

This Work has the LPPL maintenance status `author-maintained`

.

The Author of this Work is `Jean-Francois Burnol`

.

This Work consists of the files `Makefile`

, `INSTALL`

, and `xint.dtx`

and its extracted and derived files inclusive of the documentation files `xint.pdf`

, `sourcexint.pdf`

and `CHANGES.html`

.

See `xint.pdf`

for contact information.

Download the contents of this package in one zip archive (2.3M).

## xint – Expandable operations on long numbers

The xint bundle main modules are:

- xinttools
- utilities of independent interest such as expandable and non-expandable loops,
- xintcore
- expandable macros implementing addition, subtraction, multiplication, division, and powers for arbitrarily long integers,
- xint
- extension of xintcore,
- xintfrac
- extends the scope of xint to decimal numbers, to numbers using scientific notation and also to (exact) fractions,
- xintexpr
- provides expandable parsers of numeric expressions using the standard infix notations, parentheses, built-in functions, user definable functions and variables (and more ...) which do either exact evaluations (also with fractions) or floating point evaluations under a user chosen precision.

Further modules of the bundle are:
*xintkernel* (support macros for all the bundle constituents),
*xintbinhex* (conversion to and from hexadecimal and binary bases),
*xintgcd* (provides `gcd()`

and `lcm()`

functions to xintexpr),
*xintseries* (evaluates numerically partial sums of series and
power series with fractional coefficients), and
*xintcfrac* (dedicated to the computation and display of continued fractions).

All computations are compatible with expansion-only context.

The packages may be used with Plain TeX, LaTeX, or (a priori) any other macro format built upon TeX.

Package | xint |

Version | 1.4b 2020-02-25 |

Licenses | The LaTeX Project Public License 1.3c |

Copyright | 2013–2020 Jean-François Burnol |

Maintainer | Jean-François Burnol |

TDS archive | `xint.tds.zip` |

Contained in | TeX Live as xint MiKTeX as xint |

Topics | Arithmetic Calculation |