Definition

number calculate(string $expression, object $variables)

Computes a given mathematical formula using the provided variables.

Parameters

string $expression

A string representing a mathematical formula to be calculated. Consists of variables, named by the users, as well as operators and base functions.

Operators

Addition: +
Subtraction: –
Multiplication: *
Division: /
Modulo: %
Exponentiation: ^
Negation: !
Equality: ==
Less than: <
Greater than: >
Less or equal to: <=
Greater or equal to: >=
Inequality: !=
Parentheses: ()

Base functions

Function	Call	Description
sin	sin(a1)	Sine
cos	cos(a1)	Cosine
asin	asin(a1)	Arcsine
acos	acos(a1)	Arccosine
tan	tan(a1)	Tangent
cot	cot(a1)	Cotangent
atan	atan(a1)	Arctangent
acot	acot(a1)	Arccotangent
loge	loge(a1)	Natural logarithm
log10	log10(a1)	Base 10 logarithm
logn	logn(a1, a2)	Logarithm of a1 in base a2
sqrt	sqrt(a1)	Square root
if	if(a1, a2, a3)	If a1 is true, a2, otherwise a3
max	max(a1, a2, ..., a_n)	Maximum argument
min	min(a1, a2, ..., a_n)	Minimum argument
avg	avg(a1, a2, ..., a_n)	Average of the arguments
median	median(a1, a2, ..., a_n)	Median of the arguments
round	round(a1)	Round, higher at .5
random	random()	Random float between 0 and 1

object $variables

An object where the keys represent variable names, and the values represent the values to be inserted into the formula in place of their respective variables.

Returns

number

The result of the formula.

Examples

{  
  intSum: calculate('a+b', {"a": 10, "b": 20}),
  numStringSum: calculate('a+b', {"a": '10', "b": '20'}),
  floatSum: calculate('a+b', {"a": 10.5, "b": 20}), 
  intSubtract: calculate('a-b', {"a": 10, "b": 20}),
  addMultiply: calculate('(a+b)\_10', {"a": 10, "b": 20}),
  sin: calculate('sin(a)\_3', {"a": 45}),
  noVariables: calculate('(10+20)/10', null),
  logn: calculate('logn(4, 2)', `null`),
  round: calculate('round(1.5)', `null`),
  nullArg: calculate('a+b', null),                          // Error
  objArg: calculate('a+b', {}),                             // Error
  stringSum: calculate('10+b', {"b": 'aSimpleString'})      // Error
}

{  
  "intSum": 30.0,
  "numStringSum": 30.0,
  "floatSum": 30.5,
  "intSubtract": -100,
  "addMultiply": 300.0,
  "sin": 2.552710573602355,
  "noVariables": 3.0,
  "logn": 2.0,
  "round": 2.0
}

Remarks

The variables must be provided even if the formula doesn't depend on any variables, like random() or (1+2). Note that you can simply pass null in this case as the variable. Returns "NaN" on mathematically invalid input, like a negative number as an argument to the log function. Only numbers and strings with number formatting are accepted as arguments.