Inspecting calculation process | mXparser – Math Expressions Parser for JAVA, C#, C++, Kotlin, Android, .NET/MONO/Xamarin – Mathematical Formula Parser / Evaluator Library

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The tutorial consists of more than 200 live examples from 50 sections given separately for JAVA, C# and C++. Each of the examples can be copied and run on your own environment. In addition, mXparser provides an extensive collection of over 500 built-in math functions, expressions and symbols. Familiarize yourself with the scope and the syntax. Live testing is the best way to learn. Good luck! 🙂

Tutorial Math Collection API spec Download

Below is the code for JAVA, C# (the code for C# is almost identical) and C++. To copy the code, double-click inside the frame.

Case 1: Setting the verbose mode

Java/C# code

// JAVA: import org.mariuszgromada.math.mxparser.*;
// C#: using org.mariuszgromada.math.mxparser;
// ...
Function f = new Function("f(x) = x^2");
Expression e = new Expression("f(2)+(2+3)^2", f);

e.setDescription("Example - verbose mode");
e.setVerboseMode();

mXparser.consolePrintln("Res: " + e.getExpressionString() + " = " + e.calculate());

C++ code

#include "org/mariuszgromada/math/mxparser.hpp"
// ...
FunctionPtr f = new_Function("f(x) = x^2");
ExpressionPtr e = new_Expression("f(2)+(2+3)^2", f);

e->setDescription("Example - verbose mode");
e->setVerboseMode();

mXparser::consolePrintln("Res: " + e->getExpressionString() + " = " + e->calculate());

Code result

[mXparser-v.5.2.1] 
[Example - verbose mode][f(2)+(2+3)^2] 
[Example - verbose mode][f(2)+(2+3)^2] Starting...
[Example - verbose mode][f(2)+(2+3)^2] Starting calculation loop.
[Example - verbose mode][f(2)+(2+3)^2] Parsing (1, 3) ---> ( 2.0 ) ... ---> f 2.0 + ( 2.0 + 3.0 ) ^ 2.0 ...  done.
[Example - verbose mode][f(2)+(2+3)^2] Parsing (0, 1) ---> f 2.0 ... 
[f(x)][x^2] 
[f(x)][x^2] Starting...
[f(x)][x^2] x = 2.0
[f(x)][x^2] Starting calculation loop.
[f(x)][x^2] Parsing (0, 2) ---> 2.0 ^ 2.0 ... ---> 4.0 ...  done.
[f(x)][x^2] Calculated value: 4.0
[f(x)][x^2] Exiting.

---> 4.0 + ( 2.0 + 3.0 ) ^ 2.0 ...  done.
[Example - verbose mode][f(2)+(2+3)^2] Parsing (2, 6) ---> ( 2.0 + 3.0 ) ... ---> 4.0 + ( 5.0 ) ^ 2.0 ...  done.
[Example - verbose mode][f(2)+(2+3)^2] Parsing (2, 4) ---> ( 5.0 ) ... ---> 4.0 + 5.0 ^ 2.0 ...  done.
[Example - verbose mode][f(2)+(2+3)^2] Parsing (0, 4) ---> 4.0 + 5.0 ^ 2.0 ... ---> 4.0 + 25.0 ...  done.
[Example - verbose mode][f(2)+(2+3)^2] Parsing (0, 2) ---> 4.0 + 25.0 ... ---> 29.0 ...  done.
[Example - verbose mode][f(2)+(2+3)^2] Calculated value: 29.0
[Example - verbose mode][f(2)+(2+3)^2] Exiting.

Res: f(2)+(2+3)^2 = 29.0

Case 2: Syntax checking

Java/C# code

// JAVA: import org.mariuszgromada.math.mxparser.*;
// C#: using org.mariuszgromada.math.mxparser;
// ...

/* Function and expression definition */
Function fib = new Function("fib(n) = if( n>1, fib(n-1)+fib(n-2), if(n > 0, 1, 0) )");
Expression e = new Expression("fib(10) + 20/sin(x)", fib);
 
/* 1st trial of syntax checking. */
mXparser.consolePrintln("1st trial of syntax checking.");
e.checkSyntax();
mXparser.consolePrintln(e.getErrorMessage());
 
/* Definition modification */
Argument x = new Argument("x = 2");
e.addDefinitions(x);
 
/* 2nd trial of syntax checking. */
mXparser.consolePrintln("2nd trial of syntax checking.");
e.checkSyntax();
mXparser.consolePrintln(e.getErrorMessage());

C++ code

#include "org/mariuszgromada/math/mxparser.hpp"
// ...

/* FunctionPtr and expression definition */
FunctionPtr fib = new_Function("fib(n) = if( n>1, fib(n-1)+fib(n-2), if(n > 0, 1, 0) )");
ExpressionPtr e = new_Expression("fib(10) + 20/sin(x)", fib);

/* 1st trial of syntax checking. */
mXparser::consolePrintln("1st trial of syntax checking.");
e->checkSyntax();
mXparser::consolePrintln(e->getErrorMessage());

/* Definition modification */
ArgumentPtr x = new_Argument("x = 2");
e->addDefinitions(x);

/* 2nd trial of syntax checking. */
mXparser::consolePrintln("2nd trial of syntax checking.");
e->checkSyntax();
mXparser::consolePrintln(e->getErrorMessage());

Code result

[mXparser-v.5.2.1] 1st trial of syntax checking.
[mXparser-v.5.2.1] [fib(10) + 20/sin(x)]: Starting syntax check...
[fib(10) + 20/sin(x)]: Token 'fib', index 1: Starting syntax check of the user-defined function.
[fib(10) + 20/sin(x)]: -> [fib] = [if( n>1, fib(n-1)+fib(n-2), if(n > 0, 1, 0) )] Starting syntax check...
[fib(10) + 20/sin(x)]: -> [fib] = [if( n>1, fib(n-1)+fib(n-2), if(n > 0, 1, 0) )] No errors detected.
[fib(10) + 20/sin(x)]: Token 'x', index 10: Invalid token.
[fib(10) + 20/sin(x)]: Errors have been found.
[mXparser-v.5.2.1] 2nd trial of syntax checking.
[mXparser-v.5.2.1] [fib(10) + 20/sin(x)]: Starting syntax check...
[fib(10) + 20/sin(x)]: Token 'fib', index 1: Starting syntax check of the user-defined function.
[fib(10) + 20/sin(x)]: -> [fib] = [if( n>1, fib(n-1)+fib(n-2), if(n > 0, 1, 0) )] The syntax has already been checked - no errors detected.
[fib(10) + 20/sin(x)]: No errors detected.

Case 3: Just lexical syntax checking

Java/C# code

// JAVA: import org.mariuszgromada.math.mxparser.*;
// C#: using org.mariuszgromada.math.mxparser;
// ...
Expression e = new Expression("fun(1,2)+3");

mXparser.consolePrintln("checkSyntax  = " + e.checkSyntax());
mXparser.consolePrintln(e.getErrorMessage());   
mXparser.consolePrintln("checkLexSyntax = " + e.checkLexSyntax());

C++ code

#include "org/mariuszgromada/math/mxparser.hpp"
// ...
ExpressionPtr e = new_Expression("fun(1,2)+3");

mXparser_consolePrintln("checkSyntax = " + e->checkSyntax());
mXparser_consolePrintln(e->getErrorMessage());
mXparser_consolePrintln("checkLexSyntax = " + e->checkLexSyntax());

Code result

[mXparser-v.5.2.1] checkSyntax  = false
[mXparser-v.5.2.1] [fun(1,2)+3]: Starting syntax check...
[fun(1,2)+3]: Token 'fun', index 1: Invalid token.
[fun(1,2)+3]: Errors have been found.
[mXparser-v.5.2.1] checkLexSyntax = true

Case 4: Getting computing time

Java/C# code

// JAVA: import org.mariuszgromada.math.mxparser.*;
// C#: using org.mariuszgromada.math.mxparser;
// ...
Expression e = new Expression("sum(i, 1, 1000000, 1)");

mXparser.consolePrintln("Res : " + e.getExpressionString() + " = " + e.calculate());
mXparser.consolePrintln("Computing time = " + e.getComputingTime() + " s.");

C++ code

#include "org/mariuszgromada/math/mxparser.hpp"
// ...
ExpressionPtr e = new_Expression("sum(i, 1, 1000000, 1)");

mXparser_consolePrintln("Res : " + e->getExpressionString() + " = " + e->calculate());
mXparser_consolePrintln("Computing time = " + e->getComputingTime() + " s.");

Code result

[mXparser-v.5.2.1] Res : sum(i, 1, 1000000, 1) = 1000000.0
[mXparser-v.5.2.1] Computing time = 0.476 s.

Case 5: An Attempt To Fix Expression String

Java/C# code

// JAVA: import org.mariuszgromada.math.mxparser.*;
// C#: using org.mariuszgromada.math.mxparser;
// ...

/* Corrupted expression strings that can be fixed */
Expression e1 = new Expression("2++3");
Expression e2 = new Expression("2+-3");
Expression e3 = new Expression("2-+3");
Expression e4 = new Expression("2--3");
Expression e5 = new Expression("2-3+");
Expression e6 = new Expression("+2-3");
Expression e7 = new Expression("+2--3-");

mXparser.consolePrintln("An Attempt To Fix Expression String Mode is enabled by default");
mXparser.consolePrintln(e1.getExpressionString() + " -> " + e1.getCanonicalExpressionString() + ", syntax = " + e1.checkSyntax());
mXparser.consolePrintln(e2.getExpressionString() + " -> " + e2.getCanonicalExpressionString() + ", syntax = " + e2.checkSyntax());
mXparser.consolePrintln(e3.getExpressionString() + " -> " + e3.getCanonicalExpressionString() + ", syntax = " + e3.checkSyntax());
mXparser.consolePrintln(e4.getExpressionString() + " -> " + e4.getCanonicalExpressionString() + ", syntax = " + e4.checkSyntax());
mXparser.consolePrintln(e5.getExpressionString() + " -> " + e5.getCanonicalExpressionString() + ", syntax = " + e5.checkSyntax());
mXparser.consolePrintln(e6.getExpressionString() + " -> " + e6.getCanonicalExpressionString() + ", syntax = " + e6.checkSyntax());
mXparser.consolePrintln(e7.getExpressionString() + " -> " + e7.getCanonicalExpressionString() + ", syntax = " + e7.checkSyntax());

mXparser.consolePrintln("An Attempt To Fix Expression String Mode is now disabled");
e1.disableAttemptToFixExpStrMode();
e2.disableAttemptToFixExpStrMode();
e3.disableAttemptToFixExpStrMode();
e4.disableAttemptToFixExpStrMode();
e5.disableAttemptToFixExpStrMode();
e6.disableAttemptToFixExpStrMode();
e7.disableAttemptToFixExpStrMode();
mXparser.consolePrintln(e1.getExpressionString() + " -> " + e1.getCanonicalExpressionString() + ", syntax = " + e1.checkSyntax());
mXparser.consolePrintln(e2.getExpressionString() + " -> " + e2.getCanonicalExpressionString() + ", syntax = " + e2.checkSyntax());
mXparser.consolePrintln(e3.getExpressionString() + " -> " + e3.getCanonicalExpressionString() + ", syntax = " + e3.checkSyntax());
mXparser.consolePrintln(e4.getExpressionString() + " -> " + e4.getCanonicalExpressionString() + ", syntax = " + e4.checkSyntax());
mXparser.consolePrintln(e5.getExpressionString() + " -> " + e5.getCanonicalExpressionString() + ", syntax = " + e5.checkSyntax());
mXparser.consolePrintln(e6.getExpressionString() + " -> " + e6.getCanonicalExpressionString() + ", syntax = " + e6.checkSyntax());
mXparser.consolePrintln(e7.getExpressionString() + " -> " + e7.getCanonicalExpressionString() + ", syntax = " + e7.checkSyntax());

mXparser.consolePrintln("An Attempt To Fix Expression String Mode can be disabled also globally");
mXparser.disableAttemptToFixExpStrMode();
Expression e8 = new Expression("+3+-2-");
mXparser.consolePrintln(e8.getExpressionString() + " -> " + e8.getCanonicalExpressionString() + ", syntax = " + e8.checkSyntax());

C++ code

#include "org/mariuszgromada/math/mxparser.hpp"
// ...

/* Corrupted expression strings that can be fixed */
ExpressionPtr e1 = new_Expression("2++3");
ExpressionPtr e2 = new_Expression("2+-3");
ExpressionPtr e3 = new_Expression("2-+3");
ExpressionPtr e4 = new_Expression("2--3");
ExpressionPtr e5 = new_Expression("2-3+");
ExpressionPtr e6 = new_Expression("+2-3");
ExpressionPtr e7 = new_Expression("+2--3-");

mXparser::consolePrintln("An Attempt To Fix Expression String Mode is enabled by default");
mXparser::consolePrintln(e1->getExpressionString() + " -> " + e1->getCanonicalExpressionString() + ", syntax = " + e1->checkSyntax());
mXparser::consolePrintln(e2->getExpressionString() + " -> " + e2->getCanonicalExpressionString() + ", syntax = " + e2->checkSyntax());
mXparser::consolePrintln(e3->getExpressionString() + " -> " + e3->getCanonicalExpressionString() + ", syntax = " + e3->checkSyntax());
mXparser::consolePrintln(e4->getExpressionString() + " -> " + e4->getCanonicalExpressionString() + ", syntax = " + e4->checkSyntax());
mXparser::consolePrintln(e5->getExpressionString() + " -> " + e5->getCanonicalExpressionString() + ", syntax = " + e5->checkSyntax());
mXparser::consolePrintln(e6->getExpressionString() + " -> " + e6->getCanonicalExpressionString() + ", syntax = " + e6->checkSyntax());
mXparser::consolePrintln(e7->getExpressionString() + " -> " + e7->getCanonicalExpressionString() + ", syntax = " + e7->checkSyntax());

mXparser::consolePrintln("An Attempt To Fix Expression String Mode is now disabled");
e1->disableAttemptToFixExpStrMode();
e2->disableAttemptToFixExpStrMode();
e3->disableAttemptToFixExpStrMode();
e4->disableAttemptToFixExpStrMode();
e5->disableAttemptToFixExpStrMode();
e6->disableAttemptToFixExpStrMode();
e7->disableAttemptToFixExpStrMode();
mXparser::consolePrintln(e1->getExpressionString() + " -> " + e1->getCanonicalExpressionString() + ", syntax = " + e1->checkSyntax());
mXparser::consolePrintln(e2->getExpressionString() + " -> " + e2->getCanonicalExpressionString() + ", syntax = " + e2->checkSyntax());
mXparser::consolePrintln(e3->getExpressionString() + " -> " + e3->getCanonicalExpressionString() + ", syntax = " + e3->checkSyntax());
mXparser::consolePrintln(e4->getExpressionString() + " -> " + e4->getCanonicalExpressionString() + ", syntax = " + e4->checkSyntax());
mXparser::consolePrintln(e5->getExpressionString() + " -> " + e5->getCanonicalExpressionString() + ", syntax = " + e5->checkSyntax());
mXparser::consolePrintln(e6->getExpressionString() + " -> " + e6->getCanonicalExpressionString() + ", syntax = " + e6->checkSyntax());
mXparser::consolePrintln(e7->getExpressionString() + " -> " + e7->getCanonicalExpressionString() + ", syntax = " + e7->checkSyntax());

mXparser::consolePrintln("An Attempt To Fix Expression String Mode can be disabled also globally");
mXparser::disableAttemptToFixExpStrMode();
ExpressionPtr e8 = new_Expression("+3+-2-");
mXparser::consolePrintln(e8->getExpressionString() + " -> " + e8->getCanonicalExpressionString() + ", syntax = " + e8->checkSyntax());

Code result

[mXparser-v.5.2.1] An Attempt To Fix Expression String Mode is enabled by default
[mXparser-v.5.2.1] 2++3 -> 2+3, syntax = true
[mXparser-v.5.2.1] 2+-3 -> 2-3, syntax = true
[mXparser-v.5.2.1] 2-+3 -> 2-3, syntax = true
[mXparser-v.5.2.1] 2--3 -> 2+3, syntax = true
[mXparser-v.5.2.1] 2-3+ -> 2-3, syntax = true
[mXparser-v.5.2.1] +2-3 -> 2-3, syntax = true
[mXparser-v.5.2.1] +2--3- -> 2+3, syntax = true
[mXparser-v.5.2.1] An Attempt To Fix Expression String Mode is now disabled
[mXparser-v.5.2.1] 2++3 -> 2++3, syntax = false
[mXparser-v.5.2.1] 2+-3 -> 2+-3, syntax = false
[mXparser-v.5.2.1] 2-+3 -> 2-+3, syntax = false
[mXparser-v.5.2.1] 2--3 -> 2--3, syntax = false
[mXparser-v.5.2.1] 2-3+ -> 2-3+, syntax = false
[mXparser-v.5.2.1] +2-3 -> +2-3, syntax = true
[mXparser-v.5.2.1] +2--3- -> +2--3-, syntax = false
[mXparser-v.5.2.1] An Attempt To Fix Expression String Mode can be disabled also globally
[mXparser-v.5.2.1] +3+-2- -> +3+-2-, syntax = false

Nuget – Package Manager (C#, F#, Visual Basic, …)

Install-Package MathParser.org-mXparser -Version 6.1.0

Nuget – .NET CLI

dotnet add package MathParser.org-mXparser --version 6.1.0

Nuget – Package Reference

<PackageReference Include="MathParser.org-mXparser" Version="6.1.0"/>

Maven – Dependency (Java, Kotlin, Scala, Groovy, …)

<dependency> <groupid>org.mariuszgromada.math</groupid> <artifactid>MathParser.org-mXparser</artifactid> <version>6.1.0</version> </dependency>

Maven – Gradle

implementation 'org.mariuszgromada.math:MathParser.org-mXparser:6.1.0'

CMake – Dependency / FetchContent (C++, MSVC, LLVM/Clang, GNU/GCC, MinGW, MSYS2, WSL, Windows, Linux, Unix, MacOS)

include(FetchContent) FetchContent_Declare(MathParserOrgMxParserGIT_REPOSITORYhttps://github.com/mariuszgromada/MathParser.org-mXparser.gitGIT_TAGv.6.1.0SOURCE_SUBDIR CURRENT/cpp/lib ) FetchContent_MakeAvailable(MathParserOrgMxParser) target_link_libraries(YourExecutableMathParserOrgMxParser)