npm install rpn-ts

usage

import Rpn from "rpn-calculator"
const rpn = new Rpn();

const value = rpn.valueOf("sin(10ded)^ * cos(10deg)^") // 1
const value = rpn.valueOf("2x + 3!")//

if(value === null && rpn.last.details.isFunction){
   // rpn.last.details.funcVarNames // return ["x"]
	const values = rpn.valuesOf([{x: 1}, {x:2}]); // [8, 10]
}

methods

• valueOf("expression") - return value of mathematical expression or null if is functions

• valuesOf([{x: number, y:number}], ?:IExpression) - return array of values for given array of arguments - if you don't pass expression it will calculate it for last computed expression;

• last - return last computed IExpression

• lastValue - return last computed value

• expressionFrom - compute rpn expression for given string

• use(extension: func | IProcces, ?: (race: proccessedId[]) => number)

• exclude - remove given procces from computed pipe

• extend(processId: string, transform(process: IProcess) => IProcess) -extend given procc

##allowed expressions

• Values
  • "1.41545" - floated number
  • "-45" - negative number
  • "3Pi" - 3 * 3,14
  • "2e" - 2 * const e
  • "3x + 5z + 9t" - any letter is threaded as variable (expect e)
• Basic operation
  • "1 + 2" - Summation
  • "1 - 2" - Subtraction
  • "1 * 2" - Multiplication
  • "2 / 2" - Division
  • "3!" - Factorial
  • "3^" - 2 to power of 2
• Functions
  • "sin(3)" sin of number 3
  • "cos(3deg)" cos of angle 3 degrees
  • "ctg(3x)" cotangent of variable 3 * x
  • "tg(3)" tangent
  • "ln()" - natural logarithm
  • "log(3,2)" - logarithm of 3 on base 2
  • "sqrt(3)" - square root of number 3
  • "root(27, 3)" - third root of 27
  • "pow(2,5)" - 2 to power of 5
  • "abs(-4)" - absolut value of -4
  • "| -4 |" - absolute value of -4
• Grouping and organization
  • "3 * (4 + 1)" - brackets
  • "5 + [1 + 2] *2" - brackets
  • "pow(3, 5)" - comma separator of function args
• Comparisons
  • "1 > 3" - greeter
  • "1 >= 3" - greeter or equal
  • "3 < 5" - less
  • "6 <= 6" - less or equal
  • "3x = 3" - equal

expression erros

import Rpn from "rpn-calculator"
const rpn = new Rpn();

const value = rpn.valueOf("()[(pow(4)))") 
if(!value && rpn.last.errors){
    rpn.last.errors.forEach(error =>{
        console.log(error.id, error.message, error.position)
    })
    //will print 
    // EmptyBracket, Expression contains empty bracket pattern, 2
    // BracketMissmatch, Incorrect sequence of brackets, 10
    // FunctionArgument, Function power expect to have 2 arguments
}