math_parser library

Parse and evaluate mathematical expressions

A simple library done for tasks like function evaluation

Look at MathNodeExpression's fromString method for more info about how parsing works.

Parsing TL;DR

Predefined list of variables

import 'package:math_parser/math_parser.dart';

void main() {
 final expression = MathNodeExpression.fromString(
 '(2x)^(e^3 + 4) + y',
 variableNames: {'x', 'y'},
 ).calc(
   MathVariableValues({'x': 20, 'y': 10}),
 );
}

Autodetect variables

Implicit multiplication (writing 2x instead of 2*x) is not supported for auto-detecting variables. Trying to use auto-detection on expressions with implicit multiplication may cause a CantProcessExpressionException during parsing or unexpected parsing results.

import 'dart:io';
import 'package:math_parser/math_parser.dart';

void main() {
 final stringExpression = '(2*x)^(e^3 + 4) + y';
 print('Expression: $stringExpression');

 final definable = MathNodeExpression.getPotentialDefinable(
   stringExpression,
   hideBuiltIns: true,
 );

 final expression = MathNodeExpression.fromString(
   stringExpression,
   variableNames: definable.variables,
   isImplicitMultiplication: false,
 );

 // Ask user to define variables
 final variableValues = <String, double>{};
 for (final variable in definable.variables) {
   print('Enter value for $variable:');
   final double value = double.parse(
     stdin.readLineSync() as String,
   );
   variableValues[variable] = value;
 }

 final result = expression.calc(
   MathVariableValues(variableValues),
 );

 print('Result: $result');
}

Classes

MathComparison: A parent class for comparisons
MathComparisonEquation: Equation
MathComparisonGreater: If Greater Comparison
MathComparisonGreaterOrEquals: If Greater or Equals Comparison
MathComparisonLess: If Less Comparison
MathComparisonLessOrEquals: If Less or Equals Comparison
MathCustomFunctions: Set of custom functions
MathCustomFunctionsImplemented: Set of custom implemented functions
MathDefinitionFunctionFreeform: Create a new freeform function
MathDefinitionFunctionFreeformImplemented: Create a new freeform function with implementation
MathExpression: Any Math-related object
MathFunction: Mathematical function
MathFunctionAcos: The acos Function
MathFunctionAcot: The acot Function
MathFunctionAsin: The asin Function
MathFunctionAtan: The atan Function
MathFunctionCos: The cos Function
MathFunctionCot: The cot Function
MathFunctionE: The Exponent in power constant
MathFunctionFreeform: Freeform function
MathFunctionLn: The ln Function
MathFunctionLog: The log Function
MathFunctionNegative: Negative value
MathFunctionSin: The sin Function
MathFunctionTan: The tan Function
MathFunctionWithTwoArguments: Mathematical function with two arguments
MathNode: Basic math expression unit
MathOperator: Mathematical operator
MathOperatorAddition: Addition operator (+)
MathOperatorDivision: Division operator (/)
MathOperatorMultiplication: Multiplication operator (*)
MathOperatorPower: The power operation
MathOperatorSubtraction: Subtraction operator (-)
MathValue: Constant value
MathValuePi: The Pi constant
MathVariable: A math variable
MathVariableValues: Variables dictionary

Extensions

MathNodeExpression on MathExpression: Math Expression Parser Extension

Exceptions / Errors

BracketsNotClosedException: Brackets Not Closed Exception
CantProcessExpressionException: Cant Process Expression Exception
DuplicateDeclarationException: Duplicate Declaration Exception
InvalidFunctionArgumentsDeclaration: Invalid Function Arguments Declaration
InvalidFunctionNameException: Invalid Function Name Exception
InvalidVariableNameException: Invalid Variable Name Exception
MathException: Math parsing error
MathParseException: Math Parse Exception
MissingOperatorOperandException: Missing Operator Operand Exception
OutOfRangeFunctionArgumentListException: Out Of Range Function Argument List Exception
ParsingFailedException: Parsing Failed Exception
UndefinedFunctionException: Undefined Function Exception
UndefinedVariableException: Undefined Variable Exception
UnexpectedClosingBracketException: Unexpected Closing Bracket Exception
UnknownOperationException: Unknown Operation Exception

math_parser library

Parsing TL;DR

Predefined list of variables

Autodetect variables

Classes

Extensions

Exceptions / Errors

math_parser package

math_parser library