**Table of Contents**

- 1. Admin Guide
- 1.1. Overview
- 1.2. Dependencies
- 1.3. Exported Parameters
- 1.4. Exported Functions
- 1.4.1.
`math_eval(expression, result_pvar)`

- 1.4.2.
`math_rpn(expression, result_pvar)`

- 1.4.3.
`math_trunc(number, result_pvar)`

- 1.4.4.
`math_floor(number, result_pvar)`

- 1.4.5.
`math_ceil(number, result_pvar)`

- 1.4.6.
`math_round(number, result_pvar[, decimals])`

- 1.4.7.
`math_round_sf(number, result_pvar, figures)`

- 1.4.1.

- 2. Contributors
- 3. Documentation

**List of Tables**

**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

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

The following modules must be loaded before this module:

*No dependencies on other OpenSIPS modules.*.

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”.

The function evaluates a given expression and writes the result in the output pseudo-variable. The expression may contain any number of pseudo variables. 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 containing a mathematical expression. It can also include pseudo variables. The*expression*parameter can only be given as a string.*result_pvar*- pseudo-variable which will hold the result of the evaluation. Specified as a quoted string.

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))) / $avp(3)", "$avp(result)")) { xlog("Result of expression: $avp(result)\n"); } else { xlog("Math eval failed!\n"); } ...

The function evaluates a given RPN expression and writes the result in the output pseudo-variable. The expression may contain any number of pseudo variables.

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 containing a RPN expression. It can also include pseudo variables. The*expression*parameter can only be given as a string.*result_pvar*- pseudo-variable which will hold the result of the evaluation. Specified as a quoted string.

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(result)")) { 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 duplicate), compute the division of 1 by 3, then do another no-op (exponentiation then logarithm), and finally compute 1 divided by the result, giving 3 as the result. */

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*- Number to be truncated. The*number*parameter can have the following types:*string*- statically given*pvar*- value of an existing pseudo-variable (as string value - it makes no sense to truncate integers)

*result_pvar*- pseudo-variable which will hold the result of the evaluation. Specified as a quoted string.

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"); } ...

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*- Number to be truncated. The*number*parameter can have the following types:*string*- statically given*pvar*- value of an existing pseudo-variable (as string value - it makes no sense to truncate integers)

*result_pvar*- pseudo-variable which will hold the result of the evaluation. Specified as a quoted string.

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"); } ...

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*- Number to be truncated. The*number*parameter can have the following types:*string*- statically given*pvar*- value of an existing pseudo-variable (as string value - it makes no sense to truncate integers)

*result_pvar*- pseudo-variable which will hold the result of the evaluation. Specified as a quoted string.

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"); } ...

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*- Number to be rounded. The*number*parameter can have the following types:*string*- statically given*pvar*- value of an existing pseudo-variable (as string value - it makes no sense to truncate integers)

*result_pvar*- pseudo-variable which will hold the result of the evaluation. Specified as a quoted string.*decimals*- (pvar / integer as a string) which 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"); } ...

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*- Number to be rounded. The*number*parameter can have the following types:*string*- statically given*pvar*- value of an existing pseudo-variable (as string value - it makes no sense to truncate integers)

*result_pvar*- pseudo-variable which will hold the result of the evaluation. Specified as a quoted string.*figures*- (pvar / integer as a string) which 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"); } ...

**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) | 21 | 9 | 1340 | 52 |

2. | Ryan Bullock (@rrb3942) | 9 | 1 | 552 | 160 |

3. | Stephane Alnet | 6 | 2 | 327 | 36 |

4. | Razvan Crainea (@razvancrainea) | 5 | 3 | 28 | 28 |

5. | Bogdan-Andrei Iancu (@bogdan-iancu) | 4 | 2 | 2 | 1 |

6. | Julián Moreno Patiño | 3 | 1 | 3 | 3 |

*(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*

**Table 2.2. Most recently active contributors ^{(1)} to this module**

Name | Commit Activity | |
---|---|---|

1. | Bogdan-Andrei Iancu (@bogdan-iancu) | Oct 2014 - Jun 2018 |

2. | Liviu Chircu (@liviuchircu) | Feb 2013 - Jun 2018 |

3. | Razvan Crainea (@razvancrainea) | Aug 2015 - Apr 2016 |

4. | Ryan Bullock (@rrb3942) | Feb 2016 - Feb 2016 |

5. | Julián Moreno Patiño | Feb 2016 - Feb 2016 |

6. | Stephane Alnet | Nov 2013 - Nov 2013 |

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

**Last edited by:** Bogdan-Andrei Iancu (@bogdan-iancu), Liviu Chircu (@liviuchircu), Ryan Bullock (@rrb3942), Julián Moreno Patiño, Stephane Alnet.

*doc copyrights:*

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