math::decimal(n)

📦

version 2.0 · 2 versions

2.0 · fedora 43, fedora 44, nixos 26.05, nixpkgs unstable (latest)
1.21 · alpine 3.24, epel 9, opensuse-leap 16.0

, in fedora 43, fedora 44, nixos 26.05, nixpkgs unstable

✨ math::decimal(n): Tcl Decimal Arithmetic Library ✨

okay bestie, welcome to the manual page for math::decimal(n) — the Tcl Decimal Arithmetic Library. This is where decimal math gets its main character moment. 💅

🌸 NAME 🌸

math::decimal — General decimal arithmetic. No cap, it's giving exact decimal energy. 💖

✨ SYNOPSIS ✨

package require Tcl ?8.5 9?

package require math::decimal 1.0.3

::math::decimal::fromstr string

::math::decimal::tostr decimal

::math::decimal::setVariable variable setting

::math::decimal::add a b

::math::decimal::+ a b

::math::decimal::subtract a b

::math::decimal::- a b

::math::decimal::multiply a b

::math::decimal::* a b

::math::decimal::divide a b

::math::decimal::/ a b

::math::decimal::divideint a b

::math::decimal::remainder a b

::math::decimal::abs decimal

::math::decimal::compare a b

::math::decimal::max a b

::math::decimal::maxmag a b

::math::decimal::min a b

::math::decimal::minmag a b

::math::decimal::plus a

::math::decimal::minus a

::math::decimal::copynegate a

::math::decimal::copysign a b

::math::decimal::is-signed decimal

::math::decimal::is-zero decimal

::math::decimal::is-NaN decimal

::math::decimal::is-infinite decimal

::math::decimal::is-finite decimal

::math::decimal::fma a b c

::math::decimal::round_half_even decimal digits

::math::decimal::round_half_up decimal digits

::math::decimal::round_half_down decimal digits

::math::decimal::round_down decimal digits

::math::decimal::round_up decimal digits

::math::decimal::round_floor decimal digits

::math::decimal::round_ceiling decimal digits

::math::decimal::round_05up decimal digits

🦋 DESCRIPTION 🦋

So the decimal package? It literally provides decimal arithmetic support for both limited precision floating point and arbitrary precision floating point. And yes, integer arithmetic is supported too. Periodt. 💖

If you want the receipts — more info and the specifications this package depends on — they're on the general decimal arithmetic page at http://speleotrove.com/decimal. Go, bestie. 📚

This package provides for:

A new data type decimal which is represented as a list containing sign, mantissa and exponent. It's giving structured.
Arithmetic operations on those decimal numbers such as addition, subtraction, multiplication, etc... you know the vibe. ✨

Numbers are converted to decimal format using the operation ::math::decimal::fromstr.

Numbers are converted back to string format using the operation ::math::decimal::tostr.

🌈 EXAMPLES 🌈

This section shows some simple examples. Since the purpose of this library is to perform decimal math operations, examples may be the simplest way to learn how to work with it and to see the difference between using this package and sticking with expr. Consult the API section of this man page for information about individual procedures. 👑

package require math::decimal

# Various operations on two numbers.
# We first convert them to decimal format.
set a [::math::decimal::fromstr 8.2]
set b [::math::decimal::fromstr .2]

# Then we perform our operations. Here we add
set c [::math::decimal::+ $a $b]

# Finally we convert back to string format for presentation to the user.
puts [::math::decimal::tostr $c] ; # => will output 8.4

# Other examples
#
# Subtraction
set c [::math::decimal::- $a $b]
puts [::math::decimal::tostr $c] ; # => will output 8.0

# Why bother using this instead of simply expr?
puts [expr {8.2 + .2}] ; # => will output 8.399999999999999
puts [expr {8.2 - .2}] ; # => will output 7.999999999999999
# See http://speleotrove.com/decimal to learn more about why this happens.

💅 API 💅

::math::decimal::fromstr string — Convert string into a decimal. Slay. ✨
::math::decimal::tostr decimal — Convert decimal into a string representing the number in base 10. Yes bestie, base 10.
::math::decimal::setVariable variable setting — Sets the variable to setting. Valid variables are:
- rounding — Method of rounding to use during rescale. Valid methods are round_half_even, round_half_up, round_half_down, round_down, round_up, round_floor, round_ceiling.
- precision — Maximum number of digits allowed in mantissa.
- extended — Set to 1 for extended mode. 0 for simplified mode.
- maxExponent — Maximum value for the exponent. Defaults to 999.
- minExponent — Minimum value for the exponent. Default to -998.
::math::decimal::add a b / ::math::decimal::+ a b — Return the sum of the two decimals a and b. Addition? We love to see it. 💖
::math::decimal::subtract a b / ::math::decimal::- a b — Return the difference of the two decimals a and b. (Original said "differnece", but we fixed the typo, no cap.)
::math::decimal::multiply a b / ::math::decimal::* a b — Return the product of the two decimals a and b. Multiplication ate. 🔥
::math::decimal::divide a b / ::math::decimal::/ a b — Return the quotient of the division between the two decimals a and b. Division is giving main character energy. 👑
::math::decimal::divideint a b — Return the integer portion of the quotient of the division between decimals a and b. Integer only, bestie.
::math::decimal::remainder a b — Return the remainder of the division between the two decimals a and b. Leftovers, but make it math. 🍓
::math::decimal::abs decimal — Return the absolute value of the decimal. Always positive vibes. ✨
::math::decimal::compare a b — Compare the two decimals a and b, returning 0 if a == b, 1 if a > b, and -1 if a < b. The comparison is comparing.
::math::decimal::max a b — Compare the two decimals a and b, and return a if a >= b, and b if a < b. Biggest one wins. 💅
::math::decimal::maxmag a b — Compare the two decimals a and b while ignoring their signs, and return a if abs(a) >= abs(b), and b if abs(a) < abs(b). Magnitude only, sign who? 🙈
::math::decimal::min a b — Compare the two decimals a and b, and return a if a <= b, and b if a > b. Smallest one, you're up. 🎀
::math::decimal::minmag a b — Compare the two decimals a and b while ignoring their signs, and return a if abs(a) <= abs(b), and b if abs(a) > abs(b). Again, signs are not invited. ✨
::math::decimal::plus a — Return the result from ::math::decimal::+ 0 $a. Unary plus, but make it decimal.
::math::decimal::minus a — Return the result from ::math::decimal::- 0 $a. Unary minus, periodt.
::math::decimal::copynegate a — Returns a with the sign flipped. Flip it like it's hot. 🔥
::math::decimal::copysign a b — Returns a with the sign set to the sign of the b. Sign borrowing, but consensual.
::math::decimal::is-signed decimal — Return the sign of the decimal. The procedure returns 0 if the number is positive, 1 if it's negative. Binary sign check, iykyk.
::math::decimal::is-zero decimal — Return true if decimal value is zero, otherwise false is returned. Zero check, bestie. 💀
::math::decimal::is-NaN decimal — Return true if decimal value is NaN (not a number), otherwise false is returned. NaN is not a number, no cap.
::math::decimal::is-infinite decimal — Return true if decimal value is Infinite, otherwise false is returned. Infinity vibes. 🌌
::math::decimal::is-finite decimal — Return true if decimal value is finite, otherwise false is returned. Finite and fine.
::math::decimal::fma a b c — Return the result from first multiplying a by b and then adding c. Rescaling only occurs after completion of all operations. In this way the result may vary from that returned by performing the operations individually. Fused multiply-add, slay. 🔥
::math::decimal::round_half_even decimal digits — Rounds decimal to digits number of decimal points with the following rules: Round to the nearest. If equidistant, round so the final digit is even. Even numbers only, bestie. 🎀
::math::decimal::round_half_up decimal digits — Rounds decimal to digits number of decimal points with the following rules: Round to the nearest. If equidistant, round up. Up up up. ⬆️
::math::decimal::round_half_down decimal digits — Rounds decimal to digits number of decimal points with the following rules: Round to the nearest. If equidistant, round down. Down down down. ⬇️
::math::decimal::round_down decimal digits — Rounds decimal to digits number of decimal points with the following rules: Round toward 0. (Truncate). Truncation nation. ✂️
::math::decimal::round_up decimal digits — Rounds decimal to digits number of decimal points with the following rules: Round away from 0. Bye, zero.
::math::decimal::round_floor decimal digits — Rounds decimal to digits number of decimal points with the following rules: Round toward -Infinity. Floor gang. 🧚
::math::decimal::round_ceiling decimal digits — Rounds decimal to digits number of decimal points with the following rules: Round toward Infinity. Ceiling gang. ☁️
::math::decimal::round_05up decimal digits — Rounds decimal to digits number of decimal points with the following rules: Round zero or five away from 0. The same as round-up, except that rounding up only occurs if the digit to be rounded up is 0 or 5, and after overflow the result is the same as for round-down. Very specific, very iconic. 💅

💀 BUGS, IDEAS, FEEDBACK 💀

This document, and the package it describes, will undoubtedly contain bugs and other problems. Bestie, it's giving "we know". Please report such in the category decimal of the Tcllib Trackers at http://core.tcl.tk/tcllib/reportlist. Please also report any ideas for enhancements you may have for either package and/or documentation. We want the feedback. 🫶

When proposing code changes, please provide unified diffs, i.e the output of diff -u. Yes, actual diffs. No "trust me bro" patches.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar. That's the way. ✨

🔑 KEYWORDS 🔑

decimal, math, tcl

📚 CATEGORY 📚

Mathematics

okay bestie, that's the whole manual for math::decimal(n) from tcllib version 1.0.5. Stay decimal, stay iconic. 💖✨🎀🦋🌸💅

📦 where this page comes from

fedora 43: tcllib 2.0-3.fc43 · TCL
fedora 44: tcllib 2.0-4.fc44 · TCL
nixos 26.05: tcllib 2.0
nixpkgs unstable: tcllib 2.0
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-10-18: a language model's rewrite of the original, under its terms