mathops Module
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview
        1.2. Dependencies

              1.2.1. OpenSIPS Modules
              1.2.2. External Libraries or Applications

        1.3. Exported Parameters

              1.3.1. decimal_digits (integer)

        1.4. Exported Functions

              1.4.1. math_eval(expression, result_var)
              1.4.2. math_rpn(expression, result_var)
              1.4.3. math_trunc(number, result_var)
              1.4.4. math_floor(number, result_var)
              1.4.5. math_ceil(number, result_var)
              1.4.6. math_round(number, result_var[, decimals])
              1.4.7. math_round_sf(number, result_var, figures)

   2. Contributors

        2.1. By Commit Statistics
        2.2. By Commit Activity

   3. Documentation

        3.1. Contributors

   List of Tables

   2.1. Top contributors by DevScore^(1), authored commits^(2) and
          lines added/removed^(3)

   2.2. Most recently active contributors^(1) to this module

   List of Examples

   1.1. Setting the decimal_digits module parameter
   1.2. math_eval usage
   1.3. math_rpn usage
   1.4. math_trunc usage
   1.5. math_floor usage
   1.6. math_ceil usage
   1.7. math_round usage
   1.8. math_round_sf usage

Chapter 1. Admin Guide

1.1. Overview

   The mathops module provides a series of functions which enable
   various floating point operations at OpenSIPS script level.

1.2. Dependencies

1.2.1. OpenSIPS Modules

   The following modules must be loaded before this module:
     * No dependencies on other OpenSIPS modules..

1.2.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running OpenSIPS with this module loaded:
     * None.

1.3. Exported Parameters

1.3.1. decimal_digits (integer)

   The precision of the results returned by all the module
   functions. The higher the “decimal_digits” value, the more
   decimal digits the results will have.

   Default value is “6”.

   Example 1.1. Setting the decimal_digits module parameter
modparam("mathops", "decimal_digits", 10)

1.4. Exported Functions

1.4.1.  math_eval(expression, result_var)

   The function evaluates a given expression and writes the result
   in the output pseudo-variable. Evaluation uses tinyexpr (see
   https://github.com/codeplea/tinyexpr).

   Currently allowed syntax for specifying an expression:
     * Nested parentheses
     * addition (+), subtraction/negation (-), multiplication (*),
       division (/), exponentiation (^) and modulus (%) with the
       normal operator precedence (the one exception being that
       exponentiation is evaluated left-to-right)
     * C math functions: abs (calls to fabs), acos, asin, atan,
       ceil, cos, cosh, exp, floor, ln (calls to log), log (calls
       to log10), sin, sinh, sqrt, tan, tanh

   Meaning of the parameters is as follows:
     * expression (string) - a mathematical expression.
     * result_var (var) - variable which will hold the result of
       the evaluation.

   This function can be used from any route.

   Example 1.2. math_eval usage
...
# Compute some random math expression

$avp(1) = "3.141592";
$avp(2) = "2.71828";
$avp(3) = "123.45678";

if (math_eval("$avp(1) * ($avp(3) - ($avp(1) - $avp(2))) / $avp(3)", $av
p(result))) {
        xlog("Result of expression: $avp(result)\n");
} else {
        xlog("Math eval failed!\n");
}

...

1.4.2.  math_rpn(expression, result_var)

   The function evaluates a given RPN expression and writes the
   result in the output variable.

   The expression is specified in Reverse Polish Notation. Values
   are pushed onto a stack, while operations are executed on that
   stack. The following operations are supported:
     * binary operators: + - / * mod pow
     * unary functions: neg exp ln log10 abs sqrt cbrt floor ceil
       round nearbyint trunc
       neg will change the sign of the top of the stack
       ln is natural logarithm; abs is absolute value; other
       functions are standard C functions
     * constants: e pi
     * stack manipulations commands: drop dup swap

   Meaning of the parameters is as follows:
     * expression (string) - a RPN expression.
     * result_var (var) - variable which will hold the result of
       the evaluation.

   This function can be used from any route.

   Example 1.3. math_rpn usage
$avp(1) = "3";

if (math_rpn("1 $avp(1) swap swap dup drop / exp ln 1 swap /", $avp(resu
lt))) {
        xlog("Result of expression: $avp(result)\n");
} else {
        xlog("RPN eval failed!\n");
}

/* This example RPN script will push 1 then 3 onto the stack, then do a
couple no-ops
(exchange the two values twice, duplicate one of them then drop the dupl
icate),
compute the division of 1 by 3, then do another no-op (exponentiation th
en logarithm), and
finally compute 1 divided by the result, giving 3 as the result. */

1.4.3.  math_trunc(number, result_var)

   Truncation of a number towards zero. This means that trunc(3.7)
   = 3.0 and trunc(-2.9) = -2.0.

   Meaning of the parameters is as follows:
     * number (string) - Number to be truncated.
     * result_var (var) - variable which will hold the result of
       the evaluation.

   This function can be used from any route.

   Example 1.4. math_trunc usage
...
# Truncate a random number

$avp(1) = "3.141492";

if (math_trunc($avp(1), $avp(result))) {
        xlog("Truncate result: $avp(result)\n");
} else {
        xlog("Truncate failed!\n");
}
...

1.4.4.  math_floor(number, result_var)

   Truncates a number, always towards -infinity. This means that
   floor(3.7) = 3.0 and floor(-2.9) = -3.0

   Meaning of the parameters is as follows:
     * number (string) - Number to be truncated.
     * result_var (var) - variable which will hold the result of
       the evaluation.

   This function can be used from any route.

   Example 1.5. math_floor usage
...
# Truncate a random number

$avp(1) = "3.141492";

if (math_floor($avp(1), $avp(result))) {
        xlog("Floor result: $avp(result)\n");
} else {
        xlog("Floor operation failed!\n");
}
...

1.4.5.  math_ceil(number, result_var)

   Truncates a number, always towards +infinity. This means that
   ceil(3.2) = 4.0 and ceil(-2.9) = -2.0

   Meaning of the parameters is as follows:
     * number (string) - Number to be truncated.
     * result_var (var) - variable which will hold the result of
       the evaluation.

   This function can be used from any route.

   Example 1.6. math_ceil usage
...
# Truncate a random number

$avp(1) = "3.141492";

if (math_ceil($avp(1), $avp(result))) {
        xlog("Ceil result: $avp(result)\n");
} else {
        xlog("Ceil operation failed!\n");
}
...

1.4.6.  math_round(number, result_var[, decimals])

   The round function returns the nearest integer, and
   tie-breaking is done away from zero. Examples: round(1.2) =
   1.0, round(0.5) = 1.0, round(-0.5) = -1.0

   By default, the function returns an integer. An additional
   parameter controls the number of decimal digits of the initial
   number which will be kept. The rounding will then be done using
   the remaining decimal digits, and the result will be a float
   value, represented as a string.

   Meaning of the parameters is as follows:
     * number (string) - Number to be rounded.
     * result_var - variable which will hold the result of the
       evaluation.
     * decimals (int, optional) - further improves the precision
       of the rounding.

   This function can be used from any route.

   Example 1.7. math_round usage
...
# Rounding PI

$avp(1) = "3.141492";

if (math_round($avp(1), $avp(result))) {

        # result should be: 3
        xlog("Round result: $avp(result)\n");
} else {
        xlog("Round operation failed!\n");
}

...

if (math_round($avp(1), $avp(result), 4)) {

        # result should be: "3.1415"
        xlog("Round result: $avp(result)\n");
} else {
        xlog("Round operation failed!\n");
}
...

1.4.7.  math_round_sf(number, result_var, figures)

   To give a simple explanation, rounding to N significant figures
   is done by first obtaining the number resulted from keeping N
   significant figures (0 padded if necessary), then adjusting it
   if the N+1'th digit is greater or equal to 5.

   Some examples:
     * round_sf(17892.987, 1) = 20000
       round_sf(17892.987, 2) = 18000
       round_sf(17892.987, 3) = 17900
       round_sf(17892.987, 4) = 17890
       round_sf(17892.987, 5) = 17893
       round_sf(17892.987, 6) = 17893.0
       round_sf(17892.987, 7) = 17892.99

   Meaning of the parameters is as follows:
     * number (string) - Number to be rounded.
     * result_var (var) - variable which will hold the result of
       the evaluation.
     * figures - further improves the precision of the rounding.

   This function can be used from any route.

   Example 1.8. math_round_sf usage
...
# Rounding PI

$avp(1) = "3.141492";

if (math_round_sf($avp(1), $avp(result), 4)) {

        # result should be: "3.141"
        xlog("Round result: $avp(result)\n");
} else {
        xlog("Round operation failed!\n");
}

...

Chapter 2. Contributors

2.1. By Commit Statistics

   Table 2.1. Top contributors by DevScore^(1), authored
   commits^(2) and lines added/removed^(3)
     Name DevScore Commits Lines ++ Lines --
   1. Liviu Chircu (@liviuchircu) 26 12 1355 66
   2. Razvan Crainea (@razvancrainea) 10 8 39 44
   3. Vlad Patrascu (@rvlad-patrascu) 9 3 96 302
   4. Ryan Bullock (@rrb3942) 9 1 552 160
   5. Stephane Alnet 6 2 327 36
   6. Bogdan-Andrei Iancu (@bogdan-iancu) 4 2 3 1
   7. Julián Moreno Patiño 3 1 3 3
   8. Peter Lemenkov (@lemenkov) 3 1 1 1

   (1) DevScore = author_commits + author_lines_added /
   (project_lines_added / project_commits) + author_lines_deleted
   / (project_lines_deleted / project_commits)

   (2) including any documentation-related commits, excluding
   merge commits. Regarding imported patches/code, we do our best
   to count the work on behalf of the proper owner, as per the
   "fix_authors" and "mod_renames" arrays in
   opensips/doc/build-contrib.sh. If you identify any
   patches/commits which do not get properly attributed to you,
   please submit a pull request which extends "fix_authors" and/or
   "mod_renames".

   (3) ignoring whitespace edits, renamed files and auto-generated
   files

2.2. By Commit Activity

   Table 2.2. Most recently active contributors^(1) to this module
                     Name                   Commit Activity
   1. Razvan Crainea (@razvancrainea)     Aug 2015 - Oct 2019
   2. Liviu Chircu (@liviuchircu)         Feb 2013 - Jun 2019
   3. Vlad Patrascu (@rvlad-patrascu)     May 2017 - Apr 2019
   4. Bogdan-Andrei Iancu (@bogdan-iancu) Oct 2014 - Apr 2019
   5. Peter Lemenkov (@lemenkov)          Jun 2018 - Jun 2018
   6. Ryan Bullock (@rrb3942)             Feb 2016 - Feb 2016
   7. Julián Moreno Patiño                Feb 2016 - Feb 2016
   8. Stephane Alnet                      Nov 2013 - Nov 2013

   (1) including any documentation-related commits, excluding
   merge commits

Chapter 3. Documentation

3.1. Contributors

   Last edited by: Vlad Patrascu (@rvlad-patrascu), Peter Lemenkov
   (@lemenkov), Liviu Chircu (@liviuchircu), Ryan Bullock
   (@rrb3942), Julián Moreno Patiño, Stephane Alnet.

   Documentation Copyrights:

   Copyright © 2013 www.opensips-solutions.com
