Table of Contents
List of Examples
math_eval usagemath_trunc usagemath_floor usagemath_ceil usagemath_round usagemath_round_sf usageThe 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 results in the output pseudo-variable. The expression may contain any number of pseudo variables.
Currently allowed syntax for specifying an expression:
Nested parantheses
binary + - / * operators
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");
}
...
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 1.3. 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 1.4. 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 1.5. 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 1.6. 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 1.7. 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");
}
...