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Computer Algebra and Symbolic Computation in C#

C# 100.00%

computer-algebra symbolic-computation c-sharp

symbolism's Introduction

Symbolism - A Computer Algebra Library for C#

Library that implements automatic simplification of algebraic expressions in C#.

To get an idea of the kinds of expressions it handles, see the tests in this file.

The automatic simplification algorithm comes from the book "Computer Algebra and Symbolic Computation: Mathematical Methods" by Joel S. Cohen.

The core of the system is in Symbolism.cs.

Symbolism currently targets .NET Standard 2.0 and thus can be used in .NET projects on Windows, Linux, and Mac.

Nuget package available here.

Setup on Linux

Tutorial on how to build and run a simple Symbolism program on Linux.

Examples

The "PSE 5E" examples and problems in the unit tests are from the textbook "Physics for Scientists and Engineers, 5th Edition" by Serway and Jewett. Here's an index of some of the examples.

Here's a walk-through of solving a physics problem.

A slightly more complex walk-through.

Walk-through of solving a laws of motion problem.

In action:

Unit test for that example.

References

Computer Algebra and Symbolic Computation: Elementary Algorithms by Joel S. Cohen

Computer Algebra and Symbolic Computation: Mathematical Methods by Joel S. Cohen

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symbolism's Issues

This needs to be on Nuget!

Nice library. I'd like to play with it a bit, but don't have VS 2015 to build it.

Question : Parse a string to create Equation ?

Is there already a way in which I can create an equation using a string rather than static typing it.
As an update, I have created a small helper using Roslyn compiler.

Commit 59c6a6f does not build on VS 2013 / VS 2015

Hello,

I've tried to compile the most recent build 59c6a6f on both VS 2013 as well as VS 2015 - without success.

Since the only 2 files that cause issues are PolynomialDivision.cs and PolynomialGcd.cs, I'm assuming it is due to the attempt to use tuples of the System.ValueTuple nuget package, for example

public static (MathObject quotient, MathObject remainder) PolynomialDivision(MathObject u, MathObject v, MathObject x)

Could you describe in detail how you made the project compile on VS 2013 / VS 2015 ?

some dirty code to look into

I've wrote some code using Symbolism. It is interesting enough to be
shared. It is not ready to be integrated and I don't have time to
finish it. So I publish the mess as is.

The code includes:

MakeFunction() to create custom functions,
Subs() to substitute (custom) functions using callback (and
SubsFunctionStatic() to substitute variadic functions),
my own tree traversal with replacement by callback (like
DeepSelect() but goes bottom-to-top),
Output to LaTeX, either to .tex file or to .html file that includes
MathJax,
parser based on compilation (just for fun, not for real use!),
some examples of usage,
minor stuff.

https://gist.github.com/AlekseyCherepanov/53ec25566453686b95cc

Can I write canonicalized linear equation using this?

Hi,

I want all my equations to look like ax+by=c, i.e. all variables are on one side of the equation. Is it possible to do with this library? I could not find examples for doing this in the unit tests.

Thanks

Potential typo in Cos

In Cos.CosProc() should

if (n == 2)
{
    if (Mod(k, 2) == 1) return 0;
}

if (n == 2)
{
    if (Mod(k, 4) == 1) return 0;
}

This would match the pattern of modding by n*2 and the Sin.SinProc() method.

Missing Arccos func ?

Hello,

I noticed a trigo function is missing : arccos, while the arcsin (asin) function is present. Do there is a particular reason for this ?

Thanks,

Sylvain

Publish a license file to github?

The nuget package looks like Apache 2.0, consider pushing that to the license file in the repo too?

.AlgebraicExpand() hangs on C * (2 ^ (x + 1))

using System;
using Symbolism;
using Symbolism.AlgebraicExpand;

namespace my
{
    public class My
    {
        static void Main(string[] args)
        {
            var C = new Symbol("C");
            var x = new Symbol("x");
            var t = C * (2 ^ (x + 1));
            Console.WriteLine("before hang");
            t.AlgebraicExpand();
        }
    }
}

Good job. I have done some cleaning to all code

If you're interest to check it, you only have to tell me.
The changes includes:
formatted the text with the better indentation
Added LINQ expression
Invert conditions to optimise
Change recursion for cycles
etc
I'm interested in make a project based on it for Engineering Equations.
Thanks so much

.Simplify() seems confusing or inconvenient

I find .Simplify() method quite inconvenient: it is not a part
MathObject, it is a part of Sum and Product classes (and maybe some
others). It'd be more convenient to call it through general interface.

On the other hand, .Simplify() is not needed usually because Symbolism
simplifies automatically. It is needed if one changes .elts list
directly (there may be an Exception on following manipulations without
the simplification). Moving it to the interface may cause assumptions
that it is intended for regular use.

This bug report shares my concerns and documents observations. I don't
insist that it is a defect.

dharmatech / symbolism Goto Github PK

symbolism's Introduction

Symbolism - A Computer Algebra Library for C#

Setup on Linux

Examples

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References

symbolism's People

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