SySharp is simple library to symbolic calcualtions to demonstrate the power of expressions trees in C#.

The library can produce derivative function and simplify expressions.

To start the experiments you can clone the repository into your projects' directory:

cd $home/source
git clone https://github.com/markshevchenko/sysharp
cd sysharp
dotnet build -c Release

Open "C# Interactive" window in Visual Studio. Please note that csi.exe hasn't been supported the core mode, so you need Visual Studio.

Type these commands:

#reset core
#r "source/sysharp/SySharp/bin/Release/net5.0/SySharp.dll"
using SySharp;

Don't forget to check the path. source/sysharp/SySharp/bin/Release/net5.0 will be valid, if you have cloned the repository to the $home/source directory.

Now we can experiment with the library. Let's' find out the derivative of the function x²:

Symbolic.Derivative(x => x * x)

The answer is x => ((x * 1) + (1 * x)). To see it clearly we need call the ToString() method:

Symbolic.Derivative(x => x * x).ToString()

It's too complicated, isn't it?

We can simplify expressions with the help of the method Simplify():

Symbolic.Derivative(x => x * x).Simplify().ToString()

Now the anwer is x => (2 * x). Much better.

At the end we can calculate the value of derivative function:

var d = (Func<double, double>)Symbolic.Derivative(x => Math.Sin(Math.Pow(x, 3))).Compile();
d(3)

The value of the function (sin x³)' at x = 3 will be equal to -7.887747835813577.